Changes in the osmotic potential of the cell sap in passive water balance (wilting) of parts of the leaf blade were determined in relation to increasing water saturation deficit. Theoretically it could be assumed that the water lost in passive water balance comes from the total cell water equally, hence also from an aliquot part from the water contained in the cell sap. In that case the concentration of the cell sap would increase in proportion to the growing water saturation deficit. In the absolute majority of investigated cases, the osmotic pressure increased (the osmotic potential fell) more steeply than corresponded theoretically to the loss of water at the time. From the difference observed between the mentioned theoretical course and the values found, an estimate of the percentage of "mobile" water in the cell, i.e. that part which was always directly involved in changes in the water content in the cell, was calculated. This "mobile" water in adult leaves constituted about 70 to 80 per cent. The proportion of "mobile" water was dependent on the rate of development of the water saturation deficit: When the wilting was rapid the amount observed in adult leaves was smaller than in the case of slow wilting. This proved that the "mobile" proportion of the cell water is determined according to the water balance by a dynamic equilibrium of intracellular diffusion currents of water according to gradients of the potential between the different parts of cell water which are determined by different linkage ("bound" water) as well as different localization in the cell.

1. Humussäure (Humussäure Riedel-de Haen A. G. Seelze-Hannover als K-Salz) stimulierte im Dunkeln genau so wie im Lichte am stärksten die Entwicklung von Frischgewicht, Trockensubstanz und die Länge der oberirdischen Pflanzenteile bei Weizen in Kulturen mit destilliertem Wasser. Die Wachstumsstimulierung war hier so wie im Lichte mit einem signifikant niedrigeren Spiegel der einzelnen freien Zucker verbunden.
2. Im Dunkeln wurde jedoch keine signifikante Stimulierung des Wurzel-wachstums unter dem Einfluss von Humussäure festgestellt, wie es im Lichte der Fall war. Ebensowenig wurde in der Erstblattphase eine hohe Ansammlung von freien Zuckern in den Wurzeln bei der Variante Humussäre-destilliertes Wasser beobachtet, wie es im Lichte der Fall war. Der Zuckerspiegel war hier sogar niedriger als in den oberiridischen Pflanzenteilen.
3. Die Anwesenheit von Mineralnährstoffen in den Kulturen nahm bei beiden Pflanzenteilen der stimulierenden Einwirkung der Humussäure auf das Wachstum die Wirkung wie bei den Versuchen im Lichte. Ähnlich verhielt sich der Zuckerspiegel. Die Anwesenheit von Humussäure in der Nährlösung war mit einem niedrigeren Zuckerspiegel verbunden; stark beweiskräftige Unterschiede bestanden aber nur zwischen Pflanzen der Varianten mit destilliertem Wasser. Bei Wurzeln im Dunkeln stellten wir eine höhere Maltosemenge im Vergleiche mit Wurzeln aus Lichtversuchen fest.
4. Der Einfluss des Lichtes auf die oberirdischen Pflanzenteile und die Wurzeln im Zusammenhange mit Wachstum, Pflanzenstoffwechsel und dem Einfluss der Humussäure wird diskutiert.
5. Zusammenfassend kann gesagt werden, dass die Reaktion der Wurzeln auf die Einwirkung von Humussäure in bezug auf Wachstum sowie die Spiegel der einzelnen Zucker wie im Lichte deutliche Unterschiede zeigt. Die Mitwirkung der photosynthetischen Vorgänge in den Blättern bei der Beeinflussung der physiologischen Vorgänge in den Wurzeln durch Humussäure ist zu erwägen.

The effect of photoperiodic inhibition on the course of development was demonstrated by changes in the length of the sheath and the lamina, the lamina being more affected than the sheath. In a number of variants with different initiation of photoperiodic inhibition, an elongation or shortening of the sheath and the lamina of the three top leaves was observed compared with corresponding control leaves. The shortening occurred in leaves which developed beyond the normal number of the original bracts. This was the case with variants with very early inhibitions. Variants with later inhibition had on the one hand abnormally reduced leaves with imperfectly developed spikes, on the other hand elongated leaves whose length resembled that of ontogenetically younger, lower leaves. The suitability of the morphology of leaves for the investigation of the course of plant development is discussed.

The sequence of intensities with which pollen tubes utilize tested sugars from their 0.3 M solutions, is the following: sucrose >glucose >invert sugar > >fructose. The same sequence is maintained in sugar-agar media with the exception of the first two hours of incubation when sucrose, glucose and fructose are all utilized at a practically equal rate. During this period no pollen tubes were formed in the presence of fructose, in common with the sugar-free control, while in the presence of sucrose they reached a length of up to 450 µ. If sucrose was used as carrier for radioactive sugars, fructose-¹⁴C was utilized up to 12 times and glucose-¹⁴C as much as 6 times more actively than sucrose-¹⁴C. When sucrose + glucose or sucrose + fructose (in molar ratio 1 : 1) were used the pollen tubes utilized sucrose-¹⁴C at a slower rate than the corresponding monosaccharide and also at a slower rate than observed with sucrose alone. When glucose or fructose was used as carrier for sucrose-¹⁴C . the carbon dioxide-¹⁴C production by the pollen tubes was (during several time intervals of the experiment) several tens per cent higher than when sucrose served as carrier. Fructose is utilized preferentially from a medium with invert sugar.
It thus appears that the capacity of the pollen enzymic systems for incorporating the sugars tested into their respiratory pathways is as follows: fructose >glucose > sucrose, this sequence being the opposite to that found for the intensity of their growth effect and to that established for the rate of their utilization, unless present in combination. The specific growth effect of sucrose cannot thus be due primarily to the rate of its absorption or to the intensty of its utilization. The rapid rate of utilization of sucrose alone is due to the more intense growth in the presence of sucrose. The results obtained further suggest that sucrose is utilized above all via its inversion when the fructose component is respired preferentially.

Decapitated seedlings ofLinum andPisum treated with TIBA paste either above or below the cotyledons, showed different morphogenetic changes especially on the epicotyl stumps, due to the differences in the correlations of their epigeous and hypogeous cotyledons respectively, these being also primarily responsible for the differing dominance of their shoot primordia.
At the earliest phases of germination, an antagonism between TIBA and IAA can be demonstrated on the first internode inLinum, which is usually very short, as well as on the petioles of thePisum cotyledons. The former could be enlarged only by treatingLinum seeds, even when ripening on the plant, with TIBA paste and the latter, if retained by soaking seeds ofPisum in a TIBA solution could be promoted by exogenous IAA. This, on the contrary, reversed the morphogenetic effects of TIBA uponLinum seeds.

From the roots ofCucurbita pepo L. an acetone preparation was obtained with a polyphenol-oxidase activity towards pyrogallol, less marked towards pyrocatechin and DOPA. It is competitively inhibited by DIECA and KCN, but is not indibited by NaN₃, which is evidence that it is a copper enzyme of the polyphenol oxidase type. No quantitative differences between the two variants "NS" and "-Ca" were found nor qualitative differences expressed by the affinity for the substrate.

Die Ergebnisse der beschriebenen Versuche weisen darauf hin, dass in jungen Vegetationskegeln von Weizenpflanzen (2. Etappe der Organogenese), die aerobe Gärung eine wichtige Rolle spielt, während in älteren Vegetationskegeln die aeroben Oxydasensysteme in den Vordergrund treten. In den Vegetationskegeln werden die meisten Aminosäuren nicht in grösserer Menge synthetisiert, selbst wenn ihnen Aminostickstoff angeboten wird. Die wichtigste Quelle für die Eiweizsynthese stellen die aus den Blättern transportierten Aminosäuren dar. Die Umwandlung derselben im Vegetationskegel ist aber möglich. Dies geht nur unter aeroben Bedingungen vor sich. Die vorliegende Arbeit wird durch die direkte Messung der Aktivität einiger Enzyme ergänzt werden.

With the aim of finding a biochemical criterion of pollen fertility the pollen of diploid and triploid apple varieties was investigated for the content of the following aminoacids: alanine, γ-aminobutyric acid, aspartic acid, asparagine, arginine, cysteine/cystine, phenylalanine, glutamic acid, glutamine, histidine, leucine-isoleucine, proline, serine, threonine and valine. The apple pollen was found to contain the greatest amount of proline, the principal amide being asparagine. The pollen of diploid varieties contains more proline and less histidine as compared with that of the triploid ones. Both differences are highly significant. The proline-histidine quotient (PHQ) represents an important criterion of pollen fertility. Its value varied between 1.2 and 8.1 for seven triploid varieties, and between 17.5 and 53.3 for seven diploid ones. It depends not only on the variety but also on physiological conditions of the tree given by the environmental situation. The varieties tested do not significantly differ in the content of other amino-acids in pollen.

Sodium fluoride, iodoacetate and malonate inhibit or stimulate the respiration of wheat roots cultivated for 2-10 days in a solution of sodium humate (100 mg/l.) as compared with the respiration of roots cultivated in water. The influence of sodium fluoride on the respiration of leaves is similar. The ratio of the radioactivities of C¹⁴O₂ from glucose, labelled in the position 1 or 6 (C₆/C₁) is distinctly higher in roots, but not in leaves. The change in this ratio is accompanied by a decrease in the total radioactive C¹⁴O₂ from roots of plants influenced by humate, from glucose labelled specifically and totally.
Endogenous respiration (QO₂) of roots increased in humate by 5-30%, the intensity of leaf respiration remaining at the same level. The longitudinal root growth increased in humate by 20-80%, the growth of leaves by 5-15%. The above statements show that in a humate solution the glycolytic fraction of the respiratory metabolism of roots is increased.

The direct influence of irradiation on the production of anthocyanins in detached uncoloured petals of balsam cultivated in vitro was investigated. No qualitative changes occurred in the given case after irradiation. The quantitative content of anthocyanin shortly after irradiation also remained on the whole unchanged, nevertheless, after three weeks, a marked decrease in the quantitative content of anthocyanins occurred.

In studying the character of the relationship between the porphyrin metabolites containing iron and magnesium the catalytic activity of Fe-porphyrins and the possibility of their participation in chlorophyll formation in leaves and roots of plants was considered.
The results obtained elucidate the changes in the pigment content of leaves in the course of iron utilization by the plant (i.e. of the activity of iron-containing enzymes, synthesis of protohematin). The main trend of changes was observed in the following cases: (1) during utilization of various compounds affecting the individual components of the oxidation-reduction systems and the pigment content of the plant; (2) during changes of metabolism due to altered conditions of mineral nutrition: (3) in comparing the metabolism of variegated plants.
It is assumed that in all the cases the process of chlorophyll formation is directly associated with the processes of iron utilization by the plant both in the leaves and in the roots.
Data concerning the synthesis of protohematin in the isolated roots of some plants, on the activity of Fe-porphyrin enzymes therein and on the formation of chlorophylls during illumination of roots are presented. The question of the significance of synthesis of Fe- and Mg-containing porphyrins in roots for the metabolism of the whole plant is discussed.
The possible relationship between the processes of energy conservation or utilization by the cell and the equilibrium between the processes of pigment synthesis and catabolism in plastids are taken up.

In Vegetationskegeln vonTriticum aestivum von verschiedenem Entwicklungsalter wurden die organischen Säuren und der Einfluss von Malonat auf sie, wieauch auf den Qo₂ untersucht.
In der 3. und 4. Etappe der Organogenese wurden Akonitin-, Citronen-, Wein, und Phosphorsäure gefunden und ausserdem eine Ketosäure, wahrscheinlich α-Ketoglutarsäure. In der 2. Etappe der Organogenese traten Phosphor- und Milchsäure auf. Malonat beeinflusste den Qo₂ in der 2. Btappe der Organogenese nicht. In den höheren Entwicklungsetappen bewirkte es eine vollständige Atmungshemmung. Nach 2-3 Studen begannen aber die Vegetationskegel wieder normal zu atmen. Unter dem Einfluss von Malonat trat auf den Chromatogrammen von Vegetationskegeln dieses Entwicklungsalters Milchsäure und bei kurzfristiger Einwirkung des Inhibitors auch Spuren von Bernsteinsäure auf.
Die Versuchsergebnisse wurden in Hinblick auf den Ablauf des Citronensäurezyklus in Vegetationskegeln, sowie auch auf die Möglichkeit der Entstehung einer aeroben Gärung unter dem Einfluss von Malonat und dessen Abbau in den untersuchten Organen diskutiert.

A modification of the leaf-disk method of BARTOš, KUBíN and ŠETLíK (1960) is described for use in studying photosynthesis in cereals. In place of leaf-disks segments of 2 cm. in length are used. Two segments are cut by a punch from each leaf, one segment serving for the determination of dry weight at the beginning of the experiment, the second being exposed in a chamber under constant conditions. In view of the heterogeneity of the leaf, two segments from the opposite parts of the leaf must be used for each sample. A suitably modified support is also described for holding the segments in order to ensure their saturation with water. Dry weight increments of first-leaf segments of two sorts of winter wheat grown in sand cultures under artificial illumination are presented. The dry weight increment is linear in the course of 12 hours and with the sort Weibulls Banco it amounts to 51.5% which corresponds to an increment of 122.5 mg./dm.².

The results are discussed of a quantitative and qualitative analysis of the protein characters of seed-enclosed cotyledons and of hypocotyls + roots (of the primary root) of germinated seeds of the following species:Phaseolus vulgaris L.,Phaseolus coccineus L.,Phaseolus lunatus L.,Phaseolus aureus Roxb.
1. A practically identical phaseolin was found in the cotyledonsof Phaseolus vulgaris L. andPhaseolus coccineus L., being absent inPhaseolus lunatus L. andPhaseolus aureus ROXB.
2. A protein component described as Phaseolus protein III was found in the hypocotyl + root ofPhaseolus vulgaris L.,Phaseolus coccineus L. andPhaseolus lunatus L.; it was absent inPhaseolus aureus Roxb.
3. The inequality of breadth of taxonic (group) specificity of the protein characters has been confirmed anew. This fact is discussed in connection with the relative phylogenetic age of the characters, On the basis of the results obtained a developmental scheme of the studied species is proposed.

The indirect influence of irradiation on the production of anthocyanins in the blossoms of red balsam (Impatiens balsamina L.) was investigated. After 18 hrs. of swelling, seeds were irradiated with 4560 r and then changes in the anthocyanin content of blossoms were examined. In X₀ three out of four lines tested displayed a marked increase in anthocyanin content by 18%, 18% and 29%. In X₁ the quantitative content of anthocyanins either equalled that of the controls or was lower, in X₂ a significant decrease in anthocyanin content in all the lines was observed. We are apparently dealing here with a physiological effect of the type of "prolonged modifications".
In X₁ several plants with pink flowers appeared (3.4%). It is assumed that this is not due to a segregation caused by heterozygous material (the controls did not show this effect) but rather to a recessive mutation brought about by irradiation, which became apparent only in X₁.

The extent of material that had to be examined in the cytological evaluation of 40 varieties of the Czechoslovak basic assortment of pears made it necessary to work out a new, rapid method of investigation.
This method makes it possible to obtain permanent sections from about 1800 anthers within three days. During the first day, a total of three series can be imbedded in paraffin wax and each of these may contain about 600 anthers. There is sufficient time during the second day to section the three series and place the sections in gallocyanin where they are left overnight. On the following day, the sections containing about 1800 anthers are imbedded in Canadian balsam.
This method can be used with all plants having anthers sufficiently large for extirpation during the period of cell-division in the pollen mother-cells.

The reaction ofSolanum tuberosum L. after the irradiation of isolated sprouts was examined. A dose causing marked changes was sought. After a dose of 1,000 r, deformations began to appear in the tuber and stem, which increased with higher doses. Deformations of the tuber were observed after a dose of 250 r. In hybrids 4/50, nests of red-skinned potatoes were found. This property is partly preserved during the subsequent generation. The material is being further examined.

Seven strains of the clover phyllody virus originating from different localities in Slovakia were transmitted by means of the leafhopperEuscelis plebejus (Fallen) toTrifolium repens L.,T. pratense L.,T. hybridum L.,Senecio vulgaris L.,Taraxacum officinale WEB.,Chrysanthemum carinatum SCHOUSB.,Vinca rosea L. andThlaspi arvense L. Thus the ability ofE. plebejus to transmit the clover phyllody virus occurring in Slovakia was confirmed. The incubation (latent) period of virus in the vector lasted about a month and the percentage of leafhoppers which became viruliferous amounted to 30-60%. The importance of susceptible weeds in the circulation of the clover phyllody virus in nature is pointed out and the symptoms of disease caused by the individual virus strains in the plants tested are described.

The effect of CO₂ on the plasmatic structure of root-hairs of wheat and barley and the epidermal cells of onion was observed. The results were evaluated on living material with the aid of phase contrast. The root-hairs of barley and the epidermis of onion react to short exposure to an atmosphere of CO₂ by a cessation in the flow of plasma, a lengthening of the mitochondria and a rounding of the plastids.
When the influence of CO₂ lasts longer, it causes fragmentation of the mitochondria. In this phase the cells recover most quickly from the shock caused by their exposure to CO₂. When the plant is under the influence of CO₂ for too long a time, the effect is lethal. The root-hairs of wheat, which have mainly granulated mitochondria, reacted after only 40 minutes in CO₂ by a rolling-up of all the plasmatic particles.
This observation agrees with the results obtained on permanent preparations in the former work and leads to the conjecture, that by fragmentation of the mitochondria, the cell adapts itself to inhibited respiratory conditions.

1. The differences in the dynamics of the origin and further development of the water saturation deficit (WSD) in leaves of different age from 100- to 120-day-old plants of fodder cabbage and rape were investigated.
2. WSD in leaves of different age detached from plants and wilting without water supply develops most quickly in young and most slowly in old leaves. This is in basic agreement with differences in transpiration rate.
3. When entire plants are cut off, leaves of different age wilt at the same rate. In the later phases of wilting, (i.e. at a WSD value of over 20 to 30%) slightly higher WSD values were found in old leaves.
4. During slow wilting of plantsin situ, induced by decreasing soil moisture, a definite preference of young leaves in water supply was determined commencing from medium WSD values, i.e. on an average from 8 to 20%. During total lack of water in the plant, old and adult leaves wilt markedly and die off; the WSD of young leaves remains for a long time at comparatively low values.
5. In the observed preference of young leaves, the translocation of water to young leaves from the wilting older leaves takes a part.

After the application of a fractionated X-ray dose toArabidopsis thaliana L. (Heynh.) plants, chlorine type mutations (simple recessive -cc- as compared with the normal type -CC-) characterised by changed proportions of chlorophyll colouring matter as well as a decreased leaf area, retarded development in the initial phase and a substantially longer vegetative cycle, make themselves apparent. In the course of future generations, however, these characteristics change in the direction of normal types and stabilise in the sixth generation. A genetical and cytological evaluation of this manifestation showed that this mutation is connected with lesser number of plastids in the assimilative tissues. This number remains standard in all generations of the chlorine type, but on the other hand, the size of the plastids increases.

The localization of the non-specific esterase was studied by azo- coupling methods (α nyphtyl acetate or naphtol AS acetate + fast blue RR) in the root tip of the broad bean Vicia faba L. on transverse sections at different distances from the apex. With AS acetate both on frozen sections of material fixed with Baker's calcium-formol and on sections of paraffin-embedded objects, fixed with modified Wolman's acidified alcohol a positive reaction was observed in central cylinder. Different localization was observed on Baker-fixed frozen and on Wolman-fixed paraffin embedded material with a acetate. On Wolman-fixed material an intensive staining appeared in root cap and within phloem poles of central cylinder, whereas on Baker-fixed objects the inner layers of primary core were the most intensively active. Thus, our previous results have been proved and further developed.

Blätter von Nicotiana tabacum var. Xanthi-nc, die mit Gurkenmosaikvirus (CMV) systemisch infiziert worden waren, wurden mit TabakmosaikvirusPurifikat (TMV) beimpft. Beim Vergleich mit den Kontrollpflanzen wurde unter dem Einfluss von CMV eine Herabsetzung der Susceptibilität für TMV beobachtet: Die Anzahl der Läsionen sank um 64-83%; die Läsionen wuchsen langsamer und die TMV-Konzentration lag bei ihnen (im Vergleich mit der Kontrolle nach einer sechstägigen TMV-Reproduktion) um 72-90% tiefer. Interferenzerscheinungen sind nicht beobachtet worden bei einem Zeitabstand von nur sieben Tagen zwischen den Infektionen beider Viren, wurden aber bei einem Zeitintervall zwischen den Inokulierungen mit beiden Viren von 19, 34, 40 und 68 Tagen beobachtet. Die Blattgewebe von N. tabacum

Wenn wir eine Keimwurzel der Puffbohne (Vicia faba L.) mehreremale nacheinander chloralisieren, entsteht in der Aussenschicht des Pleroms und in der Innenschicht des Periblems eine grosse Anzahl polyploider Zellen, die ein unregelmässiges Mosaik bilden, aus welchem ein transversales Meristem mixoploider Seitenwurzeln entsteht. An der Entstehung einer jeden von ihnen beteiligen sich durchschnittlich ungefähr dreissig Zellen und als Folge ihrer Tätigkeit durch-laufen die Wurzel neben diploiden noch einige polyploide Stränge oder Sektoren. Die Initialen der Seitenwurzeln können zweiseitig wie ein Kambium wirksam sein oder einseitig Zellen nur für die Wurzelhaube oder nur für die eigentliche Wurzel abteilen. An der Anlage von Seitenwurzeln können sich in chloralisierten Hauptwurzeln mehrere Zellschichten beteiligen. Im Laufe der Entwicklung mixoploider Wurzeln kann manche Schichte von Initialen durch eine benachbarte Schichte ersetzt werden, wodurch der weitere Verlauf des einen oder anderen Stranges oder Sektors im Wurzelscheitel eingestellt werden kann. Diploides und mixoploides Gewebe kann sich im Wurzelquerschnitt sehr unregelmässig verteilt äussern. Dennoch können mixoploide Wurzeln eine im ganzen normale äussere Form besitzen; die Unregelmässigkeiten entstehen durch die Ausschaltung polyploider Rippen aus der weiteren Entwicklung der Wurzel oder bei eutelischen und amorphen Stämmen. In Wurzeln, in denen polyploide Zellen in der Minderzahl sind, wirken sie als fremde Elemente und werden auf verschiedene Weise aus der weiteren Entwicklung des Scheitels ausgeschlossen. In den Wurzeln geht eine Art Selbstreinigung vor sich, die zu ihrer Diploidisierung führen kann; es ist aber wahrscheinlich, dass in den Scheiteln, die sich grösstenteils aus polyploiden Zellen zusammensetzen, ein umgekehrter Vorgang vor sich gehen kann, der zu ihrer völligen Polyploidisierung führt.

In the course of seven years, mutual compatibility relations in 16 Sweet Cherry cultivars, grown in Czechoslovakia were investigated. Successful pollinations were evaluated according to the percentage of fully ripe fruits. The results obtained are summarized in Table l.The fertility as well as the pollinating ability of the individual cultivars are recorded in Table 2.
It was found that the cultivar Emperor Francis, cultivated in this country, differs from the variety of the same name grown in Western Europe, belonging to another incompatibility group and thus being also of another genotype. It must therefore be designated as Emperor Francis B. It is incompatible with Bigarreau Noir de Winkler, belonging to incompatibility group II (genotype S¹S³).
All remaining cultivars investigated are mutually compatible. Therefore, when larger plantings of these cultivars are to be established, only the time of flowering should be considered.
Further, the conditions are discussed which may cause repeated incompatibility in one direction only. The probable cause lies in flower biology (i.e. the age of blossoms of maternal plant) not in genotypic constitution.

Für eine Unterscheidung vonAgrobacterium tumefaciens undAgrobacterium rhizogenes sind drei geeignete Differenzialpflanzen gefunden worden.
1. Bryophyllum diagremontiana reagiert auf Agrobacterium tumefaciens mit der Bildung von Tumoren 32 Tage nach der Beimpfung und durch eine Stimulierung des Wuchses der Würzelchen am Rande der Tumoren (nach 52 Tagen). Bei Bryophyllum tubiflorum beträgt die Inkubationsfrist der Tumoren und der Würzelchen 30 Tage. Solanum laciniatum weist eine Inkubationsfrist für Tumoren von 15 Tagen auf, aber es kommt zu keiner Stimulierung des Würzeichenwachstums.
2. Nach einer Inokulierung mit Agrobacterium rhizogenes weisen alle drei Pflanzenarten gleiche Kennzeichen auf; Stimulierung der Würzelchen; aber die Inkubationsfrist ist verschieden (36-52 Tage), doch kommt es zu keiner Tumorbildung mehr.
3. Nach der Inokulierung mit einer Mischung von Agrobacterium tumefaciens und Agrobacterium rhizogenes bildeten sich bei Bryophyllum diagremontiana an der Impfstelle kleinere Tumoren, als bei ausschliesslicher Verwendung des Stammes Agrobacterium tumefaciens; Die Würzelchen durchwuchsen jedoch unmittelbar den Tumor. Bei Bryophyllum tubiflorum und Solanum laciniatum stimuliert die angegebene Mischung nur das Wachstum von Tumoren, die kleiner sind, als die von Agrobacterum tumefaciens hervorgerufenen und eine körnige Oberfläche haben; zu einer Stimulierung eines Würzeichenwachstums kommt es nicht.
4. Pflanzen von Bryophyllum diagremontiana wurden dekapitiert und die Schnittfläche mit Agrobacterium tumefaciens beimpft. So kam es zu einer starken Tumorbildung und zur Inhibierung des Wachstums der Achsenknospen des obersten Internodiums sowie zu seiner auffälligen Verdickung. Nach einer Inokulierung mit Agrobacterium rhizogenes kam es weder zu einer Würzelchen- noch zu einer Tumorbildung, das dekapitierte Internodium blieb am Leben, während es bei den Kontrollpflanzen eintrocknete. Nach einer Beimpfung mit einer Mischung beider Bakterien blieben die Tumoren kleiner und waren manchmal mit Würzelchen versehen, aber zu einer Verdickung des Internodiums kam es nicht.

The intensity of respiration and of photosynthesis were investigated simultaneously in sugar-beet leaves not detached from the plant. Several hours before the experiment the leaves had assimilated radioactive¹⁴CO2 whereafter they were placed into a normal leaf chamber for continuous gasometric estimation of the intensity of photosynthesis, according to the changes in the concentration of carbon dioxide in the passing air. At the same time, the specific activity of C0₂ was measured in the air that had passed through the assimilation chamber. From the values of the specific activity of CO₂ produced by the leaf in the dark the intensity of respiration in mg. CO₂ can be calculated.
It was found that sugar-beet leaves produce radioactive carbon dioxide when illuminated, both on the first and the second day after assimilation of labelled CO₂. During the considerable over-heating of leaves in the chamber when the gasometric method did not reveal anything but respiration a high production of¹⁴CO₂ could be observed radiometrically, corresponding to a higher respiration intensity. The authors explain this fact by the assumption that photosynthetic assimilation of carbon dioxide takes place simultaneously with respiration but the passive CO₂ balance in the gas exchange results in increased respiration, which actually represents the difference between the intensity of full photosynthesis and that of full respiration.
The production of carbon dioxide by whole sugar-beet leaves under illumination is no exceptional phenomenon under normal nutritional conditions.