56 Varietäten, etc. — Physiologie. — Eumycetes. 



In the hyperchromatic cells in the tapetum of phanerogams^ 

 nuclear division takes place according to a peculiar System, in 

 which a typical diakinesis stage appears — albeit with doubled 

 or manifold chromosome number; this dqes not, however, indicate 

 any reduction division. ö. Winge (Kopenhagen). 



Asher, L., Praktische Uebungen in der Physiologie» 

 Eine Anleitung für Studierende. (XI, 200 pp. kl 8«^. 21 A. 

 Berlin, J. Springer. 1916, Preis 6 Mk.) 



Das vorliegende Praktikum ist für den Mediziner bestimmt und 

 in der Weise eingerichtet, dass es in Kursen von Zwei-Semester- 

 dauer die Hauptvorlesung über Physiologie zweckmässig ergänzt. 

 Die Darstellung ist bei völliger Vermeidung von theoretischen Aus- 

 einandersetzungen ausschliesslich praktisch gehalten. Bei der Orga- 

 nisation des Praktikums war der Verf. bemüht, möglichst viele 

 Aufgaben so einfach einzurichten, dass sie von den Studierenden 

 einzeln oder in Gruppen selbständig ausgeführt werden können. 

 Einige Aufgaben über wichtige physiologischen Gesetze, die natur- 

 gemäss von Studierenden selbst nicht ausgeführt werden können ^ 

 wurden als Demonstrationsaufgaben aufgenommen. Bei der Aus- 

 wahl des Stoffes war Verf. bestrebt, eine praktische Vorführung 

 des Gesamtgebietes der Physiologie zu erreichen. 



Lakon (Hohenheim). 



Iljin, V. S., Relation of Transpiration to Assimilation in 

 Steppe Plauts. (Journ. Ecology. IV. 2. p. 65-82. 1916.) 



The investigations were made during 1913 in the government 

 of Veronezh (Russia). The author has already proved that a 

 simple comparison of the transpiration of different ecological types 

 of plants does not convey a true Impression of their water requir- 

 ments. The part played by transpiration in the plant's life is here 

 reviewed, and the basis selected is the relation between transpi- 

 ration and assimilation. Trial-methods revealed difficulties in ob- 

 taining constant ratios with rooted plants, hence cut plants were 

 used. The observations were made on a series of plants taken 

 from a ravine in the steppe, where within a Short distance there 

 were wide variations in habitat. The plants represent various 

 ecological groups, which are indicated in a series of tables giving 

 transpiration, assimilation, and the ratio transpiration in cgr. of 

 water per c. c. of decomposed carbon dioxide. Some of the author's 

 conclusions are as follows: — (1) Plants growing in dry places are 

 adapted to a more economical consumption of water; their protec- 

 tive arrangements enable them to lose less water per unit of 

 decomposed COg. (2) Mesophytes evaporate water uneconomically, 

 since they close their stomata in dry places and thus reduce 

 assimilation; in the case of xerophytes assimilation proceeds actively. 

 (3) Under normal conditions mesophytes lose less water and the 

 rate of transpiration is often slower than that of xerophytes; if 

 however the mesophytes were transferred to the dry places, their 

 transpiration increases to a greater extent than that of xerophytes. 



W. G. Smith. 



Coker, W. C, The Amanitas of the eastern United States. 



