iOO 
PHYSIOLOGY: BENEDICT AND ROTH 
growth. Breeding sister plants together in succeeding generations 
causes an automatic increase of homozygosity as is well known. This 
being a fact, cross-steriHty should increase. Such an increase in cross- 
sterility has been observed in the F3 and the F4 generations, but it would 
not be wise to maintain dogmatically that it is significant. 
1 Morgan, T. H., Some further experiments on self-fertilization in Ciona. Biol. Bull., 
8, 313-330 (1905). 
2 Morgan, T. H., Heredity and Sex. New York. Columbia University Press, ix + 1-282 
(1913). (page cited 217). 
3 Fuchs, H. M., On the conditions of self-fertilization in Ciona. Archiv. f. Entwickl. d. 
Org., 40, 157-204 (1914); The action of egg-secretions on the fertilizing power of sperm. 
Archiv. f. Entwickl. d. Org., 40, 205-252 (1914). 
4 Jost, L., Zur Physiologic des Pollens. Ber. d. deui. Bot. Ztg., Heft V and VI (1907). 
^ Correns, C, SelbststeriUtat und Individualstoffe. Festschr. d. med. nat. Gesell. zur 84. 
Versamml. deulsch. Naturforscher u. Arzle. Miinster i. W., pp. 1-32 (1912). 
THE BASAL CALORIC OUTPUT OF VEGETARIANS AS COM- 
PARED WITH THAT OF NON-VEGETARIANS OF 
LIKE WEIGHT AND HEIGHT 
By Francis G. Benedict and Paul Roth 
NUTRITION LABORATORY. CARNEGIE INSTITUTION OF WASHINGTON. 
AND THE BATTLE CREEK SANITARIUM 
Presented to the Academy, January 13. 1915 
Among the numerous, more or less scientifically attested, facts con- 
cerning the influence of a vegetarian diet are statements relative to an 
observed increase in endurance and the behef that vegetarians Hve upon 
a somewhat lower metaboKc plane than do flesh eaters, who, it is asserted, 
are unduly stimulated by the protein in their food. The measure of 
the basal gaseous metaboKsm, which may be considered as the carbon- 
dioxide production and oxygen consumption during complete muscular 
repose and in the post absorptive condition, that is, at least 12 hours 
after the last meal, gives an admirable index of the metabolic activity. 
We have been able to make observations on the basal gaseous metab- 
oKsm of 11 men and 11 women, who had subsisted upon a vegetarian 
diet for a considerable period of time, extending, on the average, over 
several years. Wi^h the subjects in the post absorptive condition and 
lying quietly upon a comfortable couch, the total carbon-dioxide pro- 
duction and oxygen consumption of each of these individuals were 
measured on several days by means of the universal respiration apparatus. 
As a rule the values obtained agree well with each other and the averages 
