NUTRITION LABORATORY. 273 



measurements of the carbon-dioxide excretion. The data substan- 

 tiate perfectly the results obtained in 1919 and supplement the previous 

 study in many important phases. This work was mainly in the hands 

 of Professor Ritzman and his assistant, Miss Helen Hilton. Special 

 tests were made by Miss AHce Johnson, Miss Mary F. Hendry, and 

 Miss Marion L. Baker, of the Laboratory staff, and a 24-hour experi- 

 ment with an ox was easily made with the cooperation of all. 



Respiration experiments on sheep. — Professor Ritzman has also used 

 the apparatus at Durham, New Hampshire, most successfully for a 

 number of experiments with groups of sheep. Several problems con- 

 nected with pregnancy and subsequent growth are now being studied 

 with these animals. 



Calorific values of extra foods. — Unusual interest has been shown by 

 physicians (and indeed the laity) in the calorimetric studies of extra 

 foods, i. e., foods taken outside of the regular meals. With special 

 emphasis upon the more or less standardized drug-store and lunch- 

 counter sandwiches, a considerable number were purchased, dried, and 

 burned in the calorimetric bomb by Mrs. Cornelia Golay Benedict, 

 assisted by Miss Mary D. Finn. The results of the work are now being 

 prepared for publication. 



Metabolism of snakes. — As representative of cold-blooded animals 

 with their peculiar thermal regulations, large snakes were studied at 

 the New York Zoological Park in continuation of the research work 

 being carried on there by the Laboratory. The principal problem 

 under investigation was the relative difference between the temperature 

 of the the snake and of its environment. As in the past few years, 

 the work has been entirely in the hands of Mr. E. L. Fox. As a further 

 illuminating phase of the work, a 3-meter boa constrictor was brought 

 to the Laboratory in Boston and intensively studied for about two 

 weeks, during which time particular attention was given to the tem- 

 perature in the cloaca and the skin temperature. The importance of 

 the vaporization of water in the thermal regulation of the snake was 

 also studied. 



Metabolism of birds. — Making use of the superior collection of birds 

 at the New York Zoological Park, we began the study of the metabol- 

 ism of various birds, particularly those of unusual physical configura- 

 tion. The work is progressing most satisfactorily with the assistance 

 of Mr. E. L. Fox. 



Conversion of carbohydrate into fat in the goose. — Our extended series 

 of observations on this important physiological problem was supple- 

 mented by several months' work with a small compensation-calori- 

 meter. The determination of the respiratory quotient under these 

 peculiar conditions by means of several methods is still being inten- 

 sively studied. 



