1916] CURRENT LITERATURE 157 
(M. S. DE Vrres) between 5° and 25° C.; protoplasmic streaming in Elodea 
d 
heart beat frequency, pulsation of aa, rhythmic muscular eebesittins 
Iti i h fre- 
di in Paramecium, generation period of certain bacteria, pupation period, 
rate of oxygen consumption, etc. 
Some high values of Q,. are found, especially in relation to life duration 
and coagulation effects of temperature. Thus, in life duration of sea ur 
eggs, Qu=240 to 1450; of Tubularia crocea, Qi=485 to 3900; of barley 
grains, Qi.=10 to 16; of spores of certain bacteria, Q1.=8, 15, 30, 50, or even 
320. In denaturing haemoglobin, Q,.=14; and in precipitation of egg white, 
Qio=635. Some processes that give normal values of Q;. within a certain tem- 
perature interval show high values of Q;. at the lower or critical temperatures. 
Thus, in CO, assimilation, Q,.= 28.7 from —6° to o° C.; in heart frequency, 
Qrw=13.7 from 3°2 to 8°4; in geotropic presentation time, Qio=20 from o° 
to 5°; in protoplasmic streaming in Vallisneria, Q=14.7 from 1°25 to 3°75. 
1z brings out more clearly the relation of temperature to life processes 
by recalculating Q,. at the various temperature intervals, instead of indicating 
only the average coefficient for a long temperature range. When this is done, 
it is found that in many cases Q, is not a constant at all intervals of tempera- 
ture. Many processes show falling values of Qo at higher temperatures, for 
example, CO, assimilation, respiration of seedlings, permeability of plant cells, 
etc. Some processes, however, show a temperature interval at which Q, is 
constant. In general, in plants the range of temperature within which Q1o 
may be constant begins at 5° C. and ends at approximately 25°C. The rapidity 
of division of B. coli shows two temperature regions with constant coefficients, 
but with different coefficient values. Investigators ‘should follow Kanirz in 
this regard, and should calculate . for each temperature interval for which 
data are available-—F. E. DENNY 
Heredity and environment 
One of the notable recent books in the general field of genetics is that of 
CONKLIN,? which is a series of lectures delivered at Northwestern University 
on the “Norman W. Harris Foundation.’’ The author has been unusually 
successful in maintaining a clear and popular style without any appreciable 
sacrifice of scientific values. The book departs from the usual type of text- 
book in genetics in several respects. In the first place, great emphasis is placed 
* Conkiin, E. G., Heredity and environment in the development of men. 8vo. 
Pp. xiv-+-533. Princeton University Press. 1915. 
