1912.^ 



1913. 75 erkrankte 

 Pflanzen, 

 nächste Nach- 

 kommenschaft 

 auch krank 



Varietäten, etc. — Physiologie. 



Nicht erkrankte Pflanze. 



35 



1 Pflanze krank, 

 mit 32'violetten 

 und 3 weissen 

 Knollen 1 



1 Pflanze nicht 



krank, mit 21 



roten und 27 



I violetten 



17 Pflanzen 

 nicht krank, 

 violette 

 Knollen. 



1914. 2 Pflanzen weisse Knollen, krank; 

 1 Pflanze weisse Knollen, nicht 

 krank. 



alle Pflanzen 8 Pflanzen, 19 Pflanzen, 

 roteKnoUen, viol. Knol- viol. Knol- 

 + krank. len, krank, len, nicht 



krank. 

 Matouschek (Wien). 



Cpocker, W. and J. F. Groves. A method ofprophesying 

 the life duration of seeds. (Proceed. Nation. Acad. Sciences. 

 I. p. 152—155. 1915.) 



Increase of the acidity of the seed will hasten coagulation of 

 the cell proteins. Such a change is known to occur in seeds of 

 certain Rosaceae, at least if stored in the imbibed condition. Le- 

 peschkin found that in active plant cells a redispersal of cell 

 proteins is going on coincidently with coagulation. As a conse- 

 quence at high temperatures where the coagulation was rapid the 

 found and calculated life durations agreed closely; while at lower 

 temperatures where redispersal is prominent the calculated life 

 durations were much shorter than the found values. In the low 

 water content of air dry seeds it is possible that the redispersal of 

 proteins is of little significance. This may limit the method to seeds 

 to relatively low water content. A slight error in a and b (Buglia's 

 formula for the coagulation of proteins runs T:=ra— blog Z, in 

 which T = temperature in degrees Centigrade, Z = time in mi- 

 nutes, a and b z=z constants) will give a relatively large error for a 

 life duration at low temperatures such as 0° C. At higher tempe- 

 ratures the error becomes less. In the data above calculated tem- 

 perature for a life duration of eight years varies little whether a 

 and b are calculated by including White's data at 20° C or merely 

 from the determinations above 70° C. The lower the water content 

 of seeds the more heating they will withstand and the greater the 

 longevity at moderate and low temperatures. This law has its limits, 

 for excessive drying is in itself injurious. In seeds that will endure 

 dessication, injury sets in with a reduction of the water much below 

 2 per Cent, while in forms like Drosera it appears before air-dry 

 condition is reached. The method of authors is, of course limited 

 to degrees of dessication less marked than those producing injury. 

 Ündoubtedly longevity under like conditions will vary with diffe- 

 rent varieties of the same species and even with diff"erent crops of 

 the same variety; but the general conditions found for a given crop 

 will probably apply to other crops of the same variety and to other 

 varieties of that species. How far the fine points mentioned above 

 will limit the application of this method can only be determinated 

 by such experiments as those outlined above. — The author has 

 experimented with Turkish Red Wheat. Matouschek (Wien). 



Lwow^, S., Ueber die Wirkung der Diastase und des 

 Emulsins auf die alkoholische Gärung und die Atmung 



