GENETICS: A. M. BANT A 
373 
tabolism of an unknown subject. An analysis of the data of actual experi- 
mentation on subjects at changing levels of nutrition shows that the changes 
in metabolism are not proportional to those in body surface. Surface area 
may not be looked upon as a determining factor in basal metabolism. 
The closest prediction of the daily heat production of a subject can be 
made by the use of the multiple regression equations, 
For men, h = 66.4730 + 13.7516 w + 5.0033 5 - 6.7550 a 
For women, h = 655.0955 + 9.5634 w + 1.8496 5 - 4.6756 a 
where h = total heat production per 24 hours, w = weight in kilograms, 
5 = stature in centimeters, and a = age in years. These equations have 
been tabulated for values of weight from 25.0 to 124.9 kgm., for stature from 
151 to 200 cm., and for age from 21 to 70 years, so that the most probable 
basal metabolism of an unknown subject may be easily determined. 
Such tables should render service in clinical and other fields of applied 
calorimetry. Their usefulness has been demonstrated in testing the typical 
or atypical nature of series of metabolism measurements, in investigating 
the differentiation of the sexes with respect to metabolic activity, of the 
metabolism of athletes as compared with non-athletic individuals, and of 
individuals suffering from disease. 
The detailed measurements and statistical constants, with full discussions 
of pertinent literature, are about to appear in Publication No. 279 of the 
Carnegie Institution of Washington. 
SEX AND SEX INTERGRADES IN CLADOCERA 
By Arthur M. Bant a 
Station for Experimental Evolution, Carnegie Institution of Washington 
Communicated by C. B. Davenport, October 18, 1918 
There is probably no one factor in the biological world of greater interest 
and importance than sex. 
Most plants are dioecious, producing the reproductive cells of both sexes 
within the same individual organism. Several lower animals are normally 
hermaphroditic but by far the larger part of the forms in the animal world 
are unisexual. 
So general is unisexuality in animals and so little thought do we in general 
give to the comparatively few normally hermaphroditic forms that we are 
accustomed to think of maleness and femaleness as opposed and mutually 
exclusive states which cannot coexist in the same organism. We are accus- 
tomed to think of maleness as indicating the possession not only of a sperm- 
producing gland and accessory reproductive structures but also the possession 
of the peculiar secondary sex character — structural, physiological, and even 
psychological and behavior characteristics. The term female implies pro- 
