THE PROTEIN SUBSTANCES. 95 



treatment it is easily seen that the common proteins are not 

 homogeneous or symmetrical bodies. On the contrary they 

 seem to contain two great groups which respond very differ- 

 ently to the action of the digestive agent, whether acid or fer- 

 ment. A part of the original complex appears to break down 

 rather quickly and go into a soluble form; while a second 

 portion resists this breaking down process pretty effectually as 

 far as weak acid and pepsin fermentation is concerned, at any 

 rate, and in subsequent treatment with the more active pan- 

 creatic ferment it yields products different from those derived 

 from the first group. To the first or less resistant fraction, 

 Kiihne gave the name hemi group, and to the second or more 

 resistant portion, the name anti group. It was later noticed 

 that most protein bodies seem to contain a third large group 

 which in the subsequent breaking down yields a sugar of some 

 kind. Hence a further or carbohydrate group may be as- 

 sumed to exist in the native protein molecules, or in most of 

 them, at least. 



Albumoses. In the first stage of the action of the acid 

 and ferment on the protein body a kind of acid albumin appears 

 which passes by continued digestion into the next or album ose 

 stage. Different albumoses seem to be derived from the sev- 

 eral native proteins, and these may be called, in general, pro- 

 teoses. Names have also been given to them corresponding to 

 their origin. We have, accordingly, fibrinoses, caseoses, 

 myosinoseSj globulinoses, and so on. Several degrees of albu- 

 mose digestion are recognized; that is, bodies are produced 

 which behave differently on treatment of the digesting mixture 

 with precipitating reagents, and we have, therefore, primary 

 and secondary albumoses. The secondary albumose stage rep- 

 resents a more advanced condition of change on digestion than 

 does the primary albumose. Finally, the secondary albumose, 

 by prolonged contact with the digestive agents, passes into the 

 peptone stage. Some idea of the existence of these three 

 stages of change may be obtained from the following experi- 

 ment in which commercial peptone is taken for illustration. 



