

1901] CURRENT LITERATURE 275 
it certainly has no effect beyond the cortex of the root when transpiration is 
active. On the other hand, the presentation of the probable relation of 
evaporation and osmosis in the mesophyll to water transfer is very satisfactory. 
The illustrations are remarkably unequal. Some are excellent; some are 
crude, but sufficient; some are so diagrammatic, without such remark, as to 
be misleading ; and some disfigure a book which deserves the best possible 
engravings. We suspect some of the worst of being relics of a long-deceased 
“botany,” resurrected from the publishers’ stock-room. Many of the illus- 
trations, though not original, are not credited to their sources, while others 
are; of this no explanation is given. 
No references are made to original papers or to other works; only in a 
few cases is the proponent of any particular view or theory referred to; and 
controverted points are scarcely alluded to. The danger from this is that the 
student may get the too common impression that the book deals out finally 
settled knowledge. It is difficult to know where to draw the line between 
the necessary dogmatism of the elementary work and the discussion of the 
treatise, but we believe in showing up the gaps in a subject fully. While 
this book only professes to be “an introduction,” it is nevertheless so thor- 
ough that it would have been improved by a selected bibliography following 
each of the various topics. For though we have Pfeffer’s treatise at hand, its 
Citations of literature are too detailed for the student of elementary physiol- 
ogy, and he would have profited greatly by the same judicious sifting of the 
literature as Professor Green has made of the facts.—C. R 
The problems of life. 
THE FUNDAMENTAL problem of physiology is the constitution of living 
matter. But we are so far from a knowledge of the chemistry of proteids, 
not to mention protoplasm, that the best we can do now is to attempt the 
framing of logical and consistent hypotheses, in the hope that these will sug- 
gest research in fruitful lines. If the true character of such hypotheses is 
kept clearly in view, they may prove helpful, but there is always a danger 
that the hypothesis may be held so aun that new facts are distorted to 
fit our interpretation of other facts. 
There is before us the first part of a work by Dr. Giglio-Tos, of the Uni- 
versity of Turin, which is an attempt to set forth a logical and consistent 
hypothesis of the organization of protoplasm and its fundamental functions, 
notably assimilation, reproduction, respiration, photosynthesis, cell 
division? A second part is to discuss ontogeny and its problems. 
LI0-Tos, ERMANNO: Les problémes de la vie: Essai d’une interpretation 
sro. mm des phénoménes vitaux. 1° partie: La substance vivant et la cytodiérése. 
vo. pp. viii 286. figs. 33. Turin: The author, Palazzo Carignano. 1900. Io 
francs 
