598 ORGANS OF GENERATION. 



which he calls livetin which only contained 0.1 per cent phosphorus and 

 which gave more monamino acids but less amide and diamino nitrogen 

 ,than vitellin. 



On the pepsin digestion of ovovitellin, OSBORNE and CAMPBELL 

 obtained a pseudonuclein with varying amounts of phosphorus, 2.52- 

 4.19 per cent. BUNGE 1 prepared a pseudonuclein by digesting the yolk 

 -with gastric juice, and his pseudonuclein, he claims, is of great 

 importance in the formation of the blood, and on these grounds he called 

 it hcematogen. This haematogen has the following composition: C 42.11, 

 H 6.08, N 14.73, S 0.55, P 5.19, Fe 0.29, and O 31.05 per cent. The 

 -composition of this substance may vary considerably even on using the 

 same method of preparation. 



Vitellin is similar to the globulins in that it is insoluble in water, but 

 on the contrary soluble in dilute neutral-salt solutions (although the solu- 

 tion is not quite transparent). It is also soluble in hydrochloric acid of 

 1 p. m. and in very dilute solutions of alkalies or alkali carbonates. It 

 is precipitated from its salt solution by diluting with water, and when 

 allowed to stand some time in contact with water the vitellin is gradually 

 changed, forming a substance more like the albuminates. The coagu- 

 lation temperature for the solution containing salt (NaCl) lies between 

 70 and 75 C., or, when heated very rapidly, at about 80 C. Vitellin 

 differs from the globulins in yielding pseudonuclein by peptic digestion. 

 It is not always completely precipitated by NaCl in substance. The 

 'ovovitellin isolated by GROSS gave MOLISCH'S reaction. NEUBERG 2 

 has also split off glucosamine from the yolk and has identified it as nori- 

 sosaccharic acid. It is difficult to state whether this glucosamine was 

 derived from the vitellin or from some other constituent of the yolk. 



The chief points in the preparation of ovovitellin are as follows: 

 The yolk is thoroughly agitated with ether; the residue is dissolved in 

 a 10-per cent common-salt solution, filtered, and the vitellin precipitated 

 by adding an abundance of water. The vitellin is now purified by repeat- 

 edly redissolving in dilute common-salt solutions and precipitating with 

 water. 



Ichthulin, which occurs in the eggs of the carp and other fishes is, accord- 

 ing to KOSSEL and WALTER, an amorphous modification of the crystalline body 

 ichthidin, which occurs in the eggs of the carp. Ichthulin is precipitated on 

 diluting with water. It was formerly considered as a vitellin. According to 

 WALTER it yields a pseudonuclein on peptic digestion; and this pseudonuclein 

 gives a reducing carbohydrate on boiling with sulphuric acid. Ichthulin has 



Haven, 1900; Gross, Zur Kenntn. d. Ovovitellins, Inaug.-Diss. Strassburg, 1899; 

 Plimmer, Journ. Chem. Soc. London, 93. 



1 Zeitschr. f. physiol. Chem., 9, 49. See also Hugounenq and Morel, Compt. rend., 

 140 and 141. 



2 Ber. d. d. chem. Gesellsch., 34. 



