06CYTIN. 



117 



properties of our second compound of casein with a non-antigenic 

 protein, globin caseinate. We find that globin is non-antigenic 

 and highly toxic, producing in guinea-pigs the typical symptoms 

 and lesions of anaphylaxis. When compounded with casein, it 

 still remains slightly toxic. An anti-serum derived by repeated 

 injections of rabbits with globin caseinate contains fixation bodies 

 for casein, globin caseinate, and, curiously enough, for globin, 

 although globin alone does not produce such antibodies. By 

 absorption experiments it may be shown that the antibodies in 

 anti-globin caseinate serum are two in number, one for casein and 

 one for globin. Thus it appears that the change in globin brought 

 about by this combination with casein renders it antigenic. 



A further study of similar and of more complex compounded 

 proteins should give further insight as to the nature of specificity. 



77 (773) 



On the nature of oocytin; the fertilizing and cytolyzing substance 

 in mammalian blood-sera. (Preliminary communication.) 



By T. Brailsford Robertson. 



[From the Rudolph Spreckels Physiological Laboratory of the Uni- 

 versity of California.] 



I have elsewhere shown 1 that the agent in ox-serum which 

 brings about the formation of fertilization-membranes in sea- 

 urchin eggs 2 can be isolated in an impure condition by a process 

 consisting, essentially, in precipitating the substance by barium 

 chloride, re-solution of this precipitate in dilute acid, removal 

 of the excess of barium by excess of sodium sulphate, and re- 

 precipitation by acetone. 



The preparations thus obtained were found to be contaminated 

 by a considerable proportion of sodium sulphate, precipitated 

 together with the fertilizing agent by the acetone. They also 



1 T. Brailsford Robertson, Journal of Biol. Chem., XI, 1912, p. 339; XII, 1912, 

 p. 163; Arch. f. Entwicklungsmech., XXXV, 1912, p. 64. 



2 J. Loeb, Arch.f. d. ges. Physiol., 118 (1907), p. 36; 122 (1908), p. 96; 124 (1908), 

 p. 37; "Die chemische Entwicklungserregung des tierischen Eies," Berlin, 1909, 

 p. 185. 



