162 Varietäten, Descendenz, Hybriden. — Physiologie. 
Ces differences de structure doivent etre attribuees aux modifi- 
cations apportees dans rassimilation chlorophyllienne et dans la 
nutrition par la vie submergee accidentelle. R. Combes. 
Laurent, H. J., Les faeteurs de la structure chez les vege- 
taux. (Rev. gen. Bot. XIX. p. 129—160. 1907.) 
Apres avoir passe en revue les differents faits physiologiques 
qui ont ete mis en lumiere dans les recherches d’anatomie experi¬ 
mentale depuis les premiers travaux qui inaugurerent cette Science, 
l’auteur precise les relations etroites qui existent entre le milieu ex- 
terieur, la Constitution physico-chimique du milieu interne des vege- 
taux et la structure anatomique de ces derniers. Rapprochant les 
nombreux resultats obtenus jusqu’ici dans cet ordre d’idees, l’auteur 
en tire des conclusions generales dont plusieurs restent encore hy- 
pothetiques mais qui pourront guider les recherches futures. 
D’apres H. J. Laurent, les faeteurs internes qui interviennent 
dans la Variation des vegetaux peuvent se ramener ä deux: 
1°. Les changements de pression osmotique, qui occasionnent 
des changements de turgescence; 
2°. La nature specifique des substances capables d’agir osmoti- 
quement. 
Si le milieu exterieur se borne reellement ä ne modifier que 
ces 2 faeteurs, il sera possible d’expliquer et de reproduire experi- 
mentalement toutes les variations que les plantes sont susceptibles 
de presenter. D’autre part, ces notions pourront encore trouver des 
applications en teratologie, pour solutionner de nombreux problemes 
restes obscurs jusqu’ici. R. Combes. 
Bose, J. C., Comparative Electro-biolog}^: a physico-phy- 
siological study (Longmans Green & Co., London 1907, 760 pp. 
with numerous illustrations, price 15 Shillings.) 
This is the concluding volume of the author’s study of ‘responsive 
phenomena’ in animals, plants and non-living matter. Prof. Bose 
throughout this work is expounding a special thesis that ‘response* 
is one and the same whelher physical or physiological and that it 
is a continuous phenomenon throughout all its manifestations in 
matter. In “Response in the Living and non Living” 1902 it 
was maintained that metal plates give similar mechanical and 
electric responses to those caracteristic of animal tissues on Stimu¬ 
lation. In “Plant Response” 1906 a detailed study of the mecha¬ 
nical responses — contraction and relaxation — in plants was expounded 
and an attempt was made to explain movements of plants of all kinds, 
including ascent of water etc. as a complex but orderly and intelli- 
gible combination of the fundamental conceptions of contraction and 
relaxation. The present volume deals with the electrical aspects of 
response in plants and a comparison with that of animals. 
These books have very special characteristics, of which one is 
that the author’s subject is so vast that the different aspects of it 
can only be expounded, as seen from the central point of view: 
There is no space for critical discussion of evidence on any special 
point. 
The book is furnished with a wealth of experimental work and 
illustrations of graphic “reeords”, over four hundred in number. 
The author’s views are highly unconventional on many points 
