178 Varietäten, etc. — Physiologie. 



from the species used by Dr. G. H. Shull (Journal of Genetics. IV. 

 1914. p. 83). 13 plants examined fall into three groups, as follows: 



1. Sterns and midribs of leaves dark crimson; buds entirely 

 green (3 exempl.). 



2. Light green stems, slightly speckled or washed with reddish; 

 midribs light green; calyces broadly striped wiih red as de Vries 

 figures (in „Gruppenweise Artbildung" pl. VIII) for Oen. hookeri. 

 (6 exempl.). 



3. Red stems and midribs, and red-striped buds. (4 exempl.). 

 The plants seem quite uniform except in color, as described 



above, and in the size of the flowers, which seems to vary largely 

 according to the condition of the plant or on the same plant ac- 

 cording to position. Oen. hewetti is a pure species, which varies or 

 mutates in Ihe same manner as other members of the genus. 



Author has a very fine plant of Oen. rubricalyx: the stems are 

 dark red, more or less streaked with green, but the midribs are 

 green, only faintly speckled with red. Thus this intensely pig- 

 mented plant has the midribs much less pigmented than in the 

 redstemmed form of hewetti, althrugh the buds are very much 

 more intensely pigmented than in ^iie latter. 



Matouschek (Wien). 



Coulter, J. M., Asuggestedexplanationof„orthogenesis" 

 in plants (Science. N. S. XLII. W 1094. p. 859-863. 1915.) 



The gymnosperms, with their unparalleled perspective, are not 

 only of importance in connection with the problems of the origin 

 of seed plants and of angiosperms, but also in developing some 

 conception of evolutionary progress quite apart from fluctuating 

 variations or even mutations, and certainly beyond the control of 

 any experimental work in genetics. It is obvious now that the phe- 

 nomenon of progressive evolution in plants is not to be explained by 

 any so called „inherent tendencj^", but rather as a continuous 

 response to progressive changes in the conditions for vegetative 

 activity. When these conditions are analyzed, the response called 

 orthogenesis in plants will become to some extent an index of the 

 evolution of climate. Matouschek (Wien). 



Hauch, L. A., Om Proveniensens Indflydelse paa Som- 

 merskud hos Eg oz Bog. [On the influence of origin 

 upon summershoots ofoak and beech]. (Botanisk Tidskrift. 

 XXXII. 2. p. 285-307. 13 fig. Köbenhavn 1915.) 



Discussion on the formation of summershoots in oak and beech 

 of danish and foreign origin. The author gives as his experience 

 that the seeds should be collected as near as possible to the place 

 where they are to be sowned. . Ove Paulsen. 



Worobiew, S. J., Versuche über den Einfluss der Erwär- 

 mung der Weizenkörner auf die Entwicklung der 

 Pflanzen. (Khosiaistwo. X. 47/48. p. 1075—1083. Kiew, 1915.) 



Verf. hat Gefässversuche mit den Früchten von Triticutn durum 

 ausgeführt, mit der Sorte „Arnaoutka" (ein Saatgut gemischt aus 

 verschiedenen Formen) und der reinen Linie der Sorte „Koubanka". 



