REVIEWS OF RECENT LITERATURE. 
GENERAL BIOLOGY. 
The Role of Water in Growth.'— Dr. C. B. Davenport has 
made an interesting series of experiments upon the eggs and 
embryos of Amblystoma, toads, and frogs to determine the propor- 
tions of water relative to the other constituents of the body during 
the earlier stages of growth. . Defining growth as “increase in 
volume,” he finds that “ exactly as in plants, there is a period of 
slow growth accompanied by abundant cell division — the earliest 
stages of the egg. There follows, after the first few hours, a period 
of rapid growth due almost exclusively to imbibed water, during 
which the percentage of water rises from 56 to 96; lastly comes 
the period of histological differentiation and deposition of formed 
substance, during which the amount of dry substance increases 
enormously, so that the percentage of water falls to 88 and below. 
But the growth is due chiefly to imbibed water.” 
Assuming for the sake of argument “that the dry substance is 
all growable,” the author finds that the curve of daily percentage 
increments based on dry weights of tadpoles fails to confirm Minot’s 
generalization that there is a “certain impulse given at the time of 
impregnation which gradually fades out, so that from the beginning 
of the new growth there occurs a diminution in the rate of growth.” 
On the contrary, he finds in tadpoles no loss in the rate of growth of 
the growing substance. He points out further that no such diminu- 
tion is noticeable in plants. 
There are one or two points in which we would take issue with 
the author. In the first place, the use of the term “plasma,” bor- 
rowed from the German, in place of “ spongioplasm ” or ‘reticulum ” 
seems to us an unfortunate one. The common use of this term is 
to designate the fluid portion of the blood, and, therefore, when it 
is used in a description of the living cell-contents it conveys a false 
impression to English readers. In the second place, it does not 
seem to us to follow, because growth as a whole is shown to be due 
to the imbibition of ‘water, that “we have to conclude, therefore, 
that all local growths are due to local imbibition of water.” It is 
' 1C. B. Davenport. Proc. Boston Soc. Nat. Hist., vol. xxviii, no. 3, pp- 73-84- 
June, 1897. 
