IN EELATION TO ZOOLOGICAL DISTINCTION. 45 



albumins present in the sera of the warm-blooded and cold-blooded animals 

 make a sharp line of demarcation between these zoological divisions. 



Mellanby (toe. cit.}, in a recent research, has confirmed Halliburton's 

 statement of the existence of only two of the three forms of serum albumin 

 in the blood of the horse. He found two albumins in the precipitated 

 proteins, 85 per cent of one and 12 per cent of the other. Wallerstein 

 (loc. cit.) records some differences in eu-fibrinoglobulin and pseudoglobulin in 

 different species. 



While it is probable that both serum globulin and serum albumin, 

 especially the latter, are of a non-unit nature, their separation into globulin 

 and albumin fractions, respectively, is still regarded as an open question. 



THE PROTEINS OF MUSCLE PLASMA AND SEEDS IN RELATION TO GENERA. 



The results of the investigations of Halliburton, Mellanby, and Waller- 

 stein have been supplemented by the researches of Przibram (Beitrage z. 

 chem. Physiologie u. Pathologic, 1902, n, 143), Rosenheim and Kajuira 

 (Journal of Physiology, 1908, xxxvi, Proceedings, p. LIV), and Osborne 

 (Science, 1908, xxvm, 417; Proc.Soc. Exper. Biology and Medicine, 1907- 

 08, v, 105) . Przibram prepared and studied the proteins of muscle plasma 

 according to the methods of Fiirth, and found that certain zoological 

 relationships exist between the kind and quantity of these substances in 

 different species. He studied 28 species, including invertebrates, fish, 

 amphibia, reptiles, birds, an embryo sheep, and a rabbit. His chief results 

 he summarizes as follows: 



A. Contain no myogen Invertebrates 



B. Contain myogen Vertebrates 



a. No precipitate with salicylate of sodium (myogen) Ammocostes (Cyclostomata?) 



6. Precipitate with salicylate of sodium (Gnathostomata?) 



a. Soluble myogenfibrin immediately after death Anamnia 



Myoprotein in increasing amount Pisces (Selachii, Teleostei) 



Myoprotein only in traces Amphibia 



6. No soluble myogenfibrin immediately after 



death (myoprotein absent) Amniota (Reptilia, Aves, Mammalia) 



Rosenheim and Kajuira record an absence of an alcohol-soluble pro- 

 tein (gliadin) and of an alcohol-insoluble protein (glutenin) from rice. 

 According to Osborne, gliadin has been found in seeds of all other grasses 

 examined (wheat, rye, oats, corn, barley, and sorghum), and glutenin forms 

 nearly 50 per cent of the gluten of wheat. 



Osborne states, from a comparative study of seed proteins, that 



No two seeds are alike in respect to their protein constituents. Similar proteins 

 are found only in seeds that are botanically closely related. The cereals are alike in the 

 proportion and general character of their proteins. The seeds of each of these, with the 

 probable exception of those of rice, contain a small amount of proteose, albumin, and 

 globulin, and relatively considerable quantities of prolamin soluble in alcohol, and of 

 glutelin insoluble in neutral solvents. With the exception of the nearly related wheat 

 and rye, the proteins soluble in alcohol from each of the cereals are distinct substances. 

 Although no certain difference has yet been detected between the gliadin of wheat and 

 of rye, their glutelins are not alike. [See Introduction, page xi.] 



The leguminous seeds are similar in the general character of their proteins, but 

 marked differences exist between the proteins of the various groups. Thus Lupinus, 



