Protoplasmic Structure 51 



the same. The ratio of carbon to nitrogen as 

 given by these configurations is slightly less than 

 the values obtained experimentally, but that may 

 be due to prosthetic fat or carbohydrate groups 

 clinging to the protein structures. 



If these polygonal compartments are filled with 

 hydrocarbon complexes as suggested in Fig. 8, 

 then we are confronted with the question of how 

 proteins absorb water. While we were consider- 

 ing the structure shown in Fig. 3, we assumed that 

 water was received directly into the hexagonal 

 compartments. Upon further consideration, how- 

 ever, it seems unlikely that the absorption of 

 water takes place in this simple manner because 

 the absorption of water is always accompanied by 

 considerable swelling which would not necessarily 

 result from the mere filling of the hexagonal com- 

 partments. It appears that absorption of water 

 and the consequent swelling can be accounted 

 for only on the assumption that the spirazines 

 straighten out during the process so as to produce 

 a sort of three-dimensional network. 



Sulphur occurs in the chemical structures of 

 nearly all proteins, but is seldom present in 

 amounts greater than two or three percent. 

 Although several different sulphur compounds 

 have been obtained from proteins upon hydrol- 



