BIOCHEMISTRY OF THE SEXUAL ORGANS 287 



a true glucoprotein and belongs to the mucoid substances. It has, 

 therefore, received the name Ovomucoid. On boiling with hydrochloric; 

 acid it yields 34 per cent, of glucosamine.^ The ovomucoid present in 

 the white of the egg amounts to about 10 per cent, of the proteins ; 

 6 per cent, of the proteins belong to the globulin group, the remainder 

 being the albumens. All the proteins of the white of the egg, not 

 only the ovomucoid, are exceptionally rich in the carbohydrate radical, 

 and on boiling with dilute hydrochloric acid yield considerable 

 quantities of glucosamine. The albumens and globulins contain about 

 10 per cent, of glucosamine. This explains perhaps the almost 

 complete absence of carbohydrates in the egg. There is the 

 further significant fact that the developing tissues of the embryo 

 are very rich in mucin, a protein containing considerable quantities 

 of glucosamine. 



The globulin fraction of the egg-white has not yet been studied 

 in detail. It is probable that it is a mixture of several globulins. 



The investigSition ''of the albumen fraction has been greatly 

 facilitated by the work of Hofmeister ^ and of Hopkins,^ which has 

 made it possible to obtain part of the albumen fraction in a crystallised 

 form. In this way Osborne and Campbell * have isolated two different 

 albumens, the crystallisable " ovalbumen " and the non-crystallisable 

 " conalbumen." Possibly even these two substances are mixtures of 

 albumens, for Bondzinski and Zoja ^ claim to have isolated from the 

 crystalhsable ovalbumen several albumens by means of fractionate 

 crystallisation. Crystalline egg albumen contains 0'13 per cent, 

 phosphorus,® and is therefore another source of phosphorus in organic 

 combination. 



The white of the eggs of some Insessores has the peculiar property 

 of forming a transparent fluorescent jelly when it is coagulated by 

 heat.'' The name " Tata-eggwhite " has been given to this substance. 

 This phenomenon is probably due to the presence of a relatively large 

 amount of basic salts in the white of the egg, since the white of a 

 hen's egg will also coagulate to a transparent jelly if the egg has been 

 kept for a few days in ten per cent, caustic potash. 



' Quoted from Ergehnisse der Physiologie, vol. i., Part I. 



2 Hofmeister, "tjber Krystallisation des Ejalbumins," Zdtsch. f. pkysiol. 

 diem., vol. xiv., 1890, and vol. xvi., 1892. 



^ Hopkins, and Pinkus, " Observations on the Crystallisation of Proteids,'' 

 Jour, of Physiol., vol. xxiii., 1898. 



^ Osborne and Campbell, Jow. Amer. Chem.. Sac, vol. xxii., 1900. 



^ Bondzinski and Zoja, "tJber die fraktionierte Krystallisation des 

 Eieralbumins," Z^itsch. f. physiol. Chem., vol. xix., 1894. 



^ Willcock and Hardy, " Preliminary Note upon the Presence of Phosphorus 

 in Crystalline Egg Albumen," Proc. Cambridge Philosophical Soc, 1907. 



"" Tarchanoff, "tJber die Verschiedenheiten des Eiereiweisses bei befiedert 

 geborenen (Nestfiiichter) und bei nakt geborenen (Nesthooker) Yogeln," 

 PflUget^s Arch.,, vol. xxxi., 1883. Tarchanoff, ''tJber Hiihnereier mit durch- 

 sichtigem Eiweiss," Pfliiger's Arch., vol. xxxix., 1883. 



