26o REPORTS ON INVESTIGATIONS AND PROJECTS. 



various embryonic tissues at different stages of embryonic growth. 

 For the nervous system a correlation between morphological and 

 chemical development is already apparent. The chemistry of em- 

 bryonic muscle is also already under investigation. 



The purin content of the liver and muscles at various embryonic 

 stages has been determined. The autolytic changes in these tissues 

 are being investigated to ascertain the chemical organization of 

 embryonic cells and the characteristics of purin metabolism. It is 

 hoped later to include some investigation of the synthesis of purin 

 compounds in the growing animal, and to ascertain whether the purin 

 metabolism of the young is essentially different from that of the adult. 



The occurrence of enzymes along the alimentary tract has also been 

 investigated. For the sugar-inverting enzymes, in the case of the 

 embryo pig, the data are ready for a preliminary report. A lactase 

 is uniformly found in the embryo intestine and presumably a maltase, 

 beginning with early embryonic life. Sucrase is apparently absent. 

 This equipment, differing from that obtained in the adult intestine, 

 bears an interesting relation to the peculiar diet (including milk 

 sugar) of the young, in contrast with the adult, in which a sucrase is 

 always present in abundance. These findings must be verified in 

 other species when suitable material becomes available. 



Finally, a study of the influence of various diets upon the proxi- 

 mate composition of the body has been begun. All the successful 

 trials up to the present have been made with mice. The experiments 

 are not yet sufficiently numerous to warrant permanent conclusions. 

 One opinion may already be tentatively expressed, namely, that with 

 diets rich in fat the percentage content of water in the body decreases, 

 but the general make-up of the fat-free tissues is probably not essen- 

 tially altered. It is hoped to extend these experiments considerably, 

 and the entire investigation will be continued with the assistance of 

 the as yet unexpended balance of the grant. 



Osbofne, Thomas B., Connecticut Agricultural Experiment Station, 

 New Haven, Connecticut. Grants Nos. 192 and 263. Appli- 

 catio7i of -methods already developed to a comparative study of the 

 more importa?it vegetable proteids. (For first report see Year Book 

 No. 3, p. III.) $5,500. 



Abstract of Reports, Gra?it No. igs {$i,§oo). — Work under this 

 grant was begun October i , 1904, and Part I of the paper, giving the 

 results of this investigation, has already been published in the Amer- 

 ican Journal of Physiology, vol. xiii, page 35, February, 1905, under 



