1903 | CURRENT LITERATURE 145 
sion. Only as an incident in the chapter on nutrition is it mentioned that 
foods temporarily stored in the chloroplasts must be transformed before 
removal, and implications of the same kind occur in connection with the 
general subject of the transfer of foods. But nowhere is there any discus- 
sion of the important part which digestion plays in plant life, nor any account 
of the agents by which it is accomplished. 
It would not be difficult to point out minor inaccuracies here and there 
in Professor Peirce’s book, nor unfortunate modes of expression; an illustra- 
tion of the latter, and one very common in physiological writings, is repeated 
many times when he speaks of natural “laws’’ as though they were objective 
and efficient agents. 
Professor Peirce’s book contains so many excellent features that it is 
unfortunate to have it marred somewhat by sins of omission and commission. 
But all these matters may be rectified in future editions without fundamentally 
changing the character of the book, which will be useful to students, par- 
ticularly if they have access to other books; and nowadays no student ought 
to get his physiological information from one source.—C. R. B. 
Diffusion and osmotic pressure. 
The rile of diffusion and osmotic pressure in plants, by Dr. Livingston, is 
a well-made and attractive-looking volume of 149 pages, constituting one of 
the Decennial Publications of the University of Chicago.? 
For several years the need of a concise, yet sufficiently detailed, state- 
ment of the facts and modern theories of diffusion and osmosis, on both 
_ the physical and the physiological side, has been felt by every student and 
teacher of physiology. Such a volume has now appeared. 
Dr. Livingston has divided his book into two parts, one dealing with 
physical and the other with physiological considerations. In the first part we 
have Matter and its states, Diffusion and diffusion tension, Liquid solutions, 
Ionization, Osmotic phenomena, Measurement and calculation of osmotic 
pressure; and in the second part Turgidity, Absorption and transmission of 
water, Absorption and transmission of solutes, Influence of the osmotic 
pressure of the surrounding medium upon organisms. 
After stating briefly the theories of matter, the author proceeds to the 
consideration of the diffusion of gases, liquids, and solids, and then in the fol- 
lowing chapter discusses in a lucid manner the difficult subject of solutions, 
using this opportunity to repeat and apply the teachings of the preceding 
chapter on diffusion, and showing his regard for the needs of the student by 
defining such terms as zorma/ solution, gram-molecule solution, and gram- 
equivalent solution. 
? LivINGsToN, Burton E., The role of diffusion and osmotic pressure in plants. 
Decennial Publications of the University of Chicago, Second Series, Vol. VIII. 8vo. 
pp- xvi-++149. University of Chicago Press. 1903. ‘ 
