SECT. 9] PROTEIN METABOLISM 1125 



Table 157. 



Evidently (setting apart the last value, which is doubtful) there is 

 here to be seen the same fall in intensity of production of nitrogenous 

 waste which appeared above from the data of Majevski and of 

 Tschernov — the former set indeed, fit on, as it were, at the upper end 

 of Doderlein's. But the mere determination of non-protein nitrogen 

 in the liquids does not carry us very far, and we find a much more 

 thorough attack on the nitrogen excretion of the mammalian embryo 

 in the work of Lindsay. Table 158 summarises the more important 

 points emerging from her data. They were confined to herbivorous 

 animals, the sheep and the cow, and, as the figures show, they were 

 quite concordant. In both cases there was no ammonia in the foetal 

 urine, although it was present in that of the adult. The sheep's 

 allantoic urine contained a good proportion of allantoin, but not 

 the cow's, and a very notable thing was the high proportion of 

 amino-acids other than hippuric acid. Creatine and creatinine 

 were always present, and in much the same amount, but perhaps 

 the most extraordinary finding was that the urea of the foetal urine 

 was very low, its percentage value being about half that of the adult 

 urine, a deficiency made up by a large amount of unidentified 

 nitrogen. This unidentified nitrogen confirmed the earlier work of 

 Panzer and of Paton, Watson & Kerr, and recalls the similar assertion 

 of Targonski in the case of the chick. Lindsay made a determined 

 attempt to discover its nature, but without much success, although 

 she established the fact that it was all present in the phosphotungstic 

 acid precipitate. It was therefore probably polypeptides or di-amino- 

 acids, and it could not have been proteoses or peptones, for the 



