92 THE PROTEIN SUBSTANCES. 



B. ALBUMINOIDS OR ALBUMOIDS. 

 Keratins. 

 Elastin. 



Collagen and glutin. 

 Reticulin. 



(Fibroin, Sericin, Coilin, Cornein, Spongin, Byssus, and others.) 

 C. CLEAVAGE PRODUCTS OF TRUE ALBUMINOUS BODIES. 



Alkali and Acid Albuminates. 

 Proteoses, Peptones, Polypeptides. 

 (Amino-acids.) 



n. Compound Proteins. 



I Mudn substances. 



Glycoproteins 



Nucleoproteins. 



f HcBmoglobin, 

 Chromoproteins ............... \ TT 



[ Hcemocyamn. 



As there are two classifications recognized by English-speaking scien- 

 tists we will give the classifications adopted by the American Physio- 

 logical Society and the American Society of Biological Chemists and 

 also the British Medical Association. 



Classification adopted by the American Physiological Society and 

 the American Society of Biological Chemists : 



I. Simple Proteins. 



A. Albumins. 



B. Globulins. 



C. Glutelins. 



D. Prolamins (Alcohol-soluble proteins). 



E. Albuminoids. 



F. Histones. 



G. Protamines. 



n. Conjugated Proteins. 



A. Nucleoproteins. 



B. Glycoproteins. 



C. Phosphoproteins. 



D. Haemoglobins. 



E. Lecithoproteins. 



