470 Proceedings Columbia Biochemical Association [April-July 



protein fractions were analysed by Van Slyke's method. The fol- 

 lowing conclusions are drawn: 



There are two yellow pigments in the eggs, one being soluble in 

 ether, the other insoluble in ether but soluble in alcohol. 



There is a total loss in dry weight (carbon dioxid and water) 

 during the development of loo eggs to the hatching stage of 

 0.0969 gm. 



There is a gain of fats in the development of the tgg to larva, 

 the ether extract rising from 1.1182 gm. per 100 eggs to 1.2747 gm. 

 per 100 larvae. 



There is a loss in ether-insoluble but alcohol-soluble substance 

 of from 0.6630 gm. in 100 eggs to 0.6179 g^^- ^'^ 100 larvae. 



There is a loss in the protein fraction, the weight falling from 

 4.0256 gm. in 100 eggs to 3.8278 gm. in 100 larvae. 



There is neither gain nor loss of nitrogen in development; 100 

 eggs = 0.5849 gm. N., 100 larvae = 0.5845 gm. N. 



There is a gain of nitrogen in the ether-soluble portion of from 

 0.0025 gm. to 0.0045 gni- This indicates a synthesis of 0.1174 gm. 

 of lecithin (1.73 percent N.) providing all of the nitrogen in the 

 ether-soluble portion is counted as lecithin. 



There is a gain of nitrogen in the ether-insoluble but alcohol-sol- 

 uble portion of from 0.0070 gm. to o.oi 1 1 gm. The nitrogen in this 

 fraction is largely basic nitrogen, probably purin or pyrimidin bases. 



There is a loss of 0.0066 gm. of nitrogen from the protein frac- 

 tion. Nearly all of this loss comes from the mon-amino acids. 



Tangl and Parkas'^ ^ hypothesis, as postulated for the trout eggs, 

 does not hold true, i. e., that when there is a gain of fats this gain 

 comes from the glycoproteins, the nitrogen of the protein being re- 

 tained in the organism in the form of urea or uric acid. It seems 

 probable that the carbohydrate portion of a glycoprotein (ovomu- 

 coid?) furnishes the "Entwicklungsarbeit" of Cryptobranchus 

 eggs, and that the energy released by the breaking down of the 

 carbohydrate is more than sufficient for the energy of development 

 and as a result fat is synthesized. The nitrogen of the glycopro- 

 tein however is not broken down to either urea or uric acid. Urea 

 nitrogen would appear in the ether-soluble portion (see preceding 

 abstract) but an increase of only 0.00035 g^n. of ammonia nitrogen 



12 Tangl and Farkas : Arch. ges. Fhysiol., 1908, civ, pp. 624-38. 



