754 



THE RESPIRATION AND 



[PT. Ill 



no relation between heat-production and this factor, but as they 

 neglected to estimate the total nitrogen, and so did not calculate the 

 chemical nucleoplasmic ratio, their figures cannot be compared 

 directly with those of LeBreton & Schaeffer for change with age. 



Then Moulton's figures on the cow for nitrogen content of whole 

 animals have often been taken 



'^ uiciprifctyrri 



Liver 



10 



S 5 



Diaphragm 

 Muscle 



as evidence in favour of a 

 direct relation between sur- 

 face and total protein, but 

 for small animals, Terroine, 

 Brenckmann & Feuerbach 

 could not find such a con- 

 dition. Terroine, in his review 

 of the subject, considers vari- 

 ous other possible measures of 

 the active mass, such as the 

 work of Mayer & Schaeffer on 

 lipoids, and that of Lapicque 

 & Petetin on mineral con- 

 stituents. He is, of course, con- 

 cerned throughout to show 

 that, as far as the evidence 

 goes, the composition of all 

 animals is practically the 

 same, and cites with special 

 approval the investigations 

 of Abderhalden, Gigon & 

 Strauss, of Osborne & Jones 

 and of Osborne & Heyl, who 

 found very similar amino-acid 

 distributions in proteins from 

 a mammal, a bird, a fish and 

 a mollusc. Nevertheless, such arguments are not at all convincing, 

 for they essentially consist in minimising the differences which have 

 been found to exist, and it would be equally justifiable in the present 

 state of our knowledge to emphasise small variations just as much. 

 The fact is that we cannot as yet be sure on the ground of the chemical 

 analyses we have whether protoplasms of different animals are dif- 

 ferent or the same, and, until a great deal more work has been done, 



Q. 

 I. 

 O 



Fig. i( 



