II24 PROTEIN METABOLISM [pt. m 



liquid occurred, but also genuine discontinuous micturition, at any rate 

 during the late stages, for he often found (69 per cent.) the bladders 

 of newborn human infants to be full. This had already been the 

 view of Englisch; Dohrn; Betschler; and many other obstetricians. 

 According to Keene & Hewer who experimented with vital dyes, 

 and to Hewer who used differential staining methods, the excretory 

 activity of the human kidney begins as early as the loth to the 

 1 2th week. Similarly Firket found that the cat's kidney can 

 excrete sodium ferricyanide and ferric ammonium citrate before 

 the glomeruli are fully differentiated. Mijsberg even has reasons 

 for supposing that the human pronephros is functional (see also 

 Fritschek) . 



Gusserov reported the presence of allantoin in the urine of pregnant 

 women, and therefore concluded that the foetus possessed an active 

 uricase, but this idea was exploded by Wiechovski who found no 

 traces of it, and finally Wells & Corper discredited Cannata's asser- 

 tion of the presence of uricase in the human placenta. Gusserov's 

 original observation must have been a mistake, but he has the merit of 

 being among the first to investigate the subject. It is not necessary 

 here to detail the work of those investigators who have published 

 results for urea, uric acid content, etc., of the blood of newborn 

 infants (e.g. Martin, Ruge & Biedermann; Dohrn; Hofmeier, etc.) 

 for the processes of parturition introduce too many doubtful factors. 

 An interesting piece of work was later done by Feis, who found 

 that urea injected hypodermically is a strong poison for the embryo 

 rabbit, which cannot withstand the same degree of uraemia as the 

 mother. In 1902 Panzer, in examining an hydropic foetus, was 

 able to collect embryonic urine unmixed with amniotic liquid. 

 Of specific gravity i-oo8, it contained traces of protein, no glucose, 

 keto-substances, or indican, and no creatinine. The nitrogen partition 

 was peculiar, urea accounting for only 40 per cent, of the total 

 nitrogen and uric acid for 15-5 per cent., the rest being in some 

 unknown form. 



Doderlein in 1890 made a detailed investigation of many aspects 

 of the amniotic and allantoic liquids of the cow, and among his 

 observations was a series on the non-protein nitrogen of both. 

 Assuming that the preponderant part of this could be counted as 

 waste nitrogen, it is easy to calculate it per 100 gm. wet weight of 

 embryo, with the results which follow: 



