750 THE RESPIRATION AND [pt. iii 



Those who have not accepted these opinions have chosen rather 

 to agree with St Paul's affirmation that "all flesh is not the same 

 flesh, but there is one kind of flesh of men, another flesh of beasts, 

 another of fishes, another of birds", and to maintain that proto- 

 plasms are not identical. A mouse diflfers from an elephant not 

 because the surface was the element given in the first instance, and 

 heat must be provided to compensate for that escaping at the surface, 

 but because the metabolic constitution of its protoplasm differs, and 

 therefore its surface. Or, in other words, the circulatory and re- 

 spiratory systems do not govern the respiratory intensity of the 

 tissues, but on the contrary were themselves laid out to meet a certain 

 demand. "Thermogenese", in other words, is for these thinkers the 

 cause of "thermolyse". An animal grows until it reaches a point at 

 which its surface cannot be further reduced proportionately to its 

 weight without involving a failure to carry away the appropriate 

 portion of heat generated. An animal has, or may have, a surface 

 proportional to its heat-production, and not a heat-production pro- 

 portional to its surface. The fact that the heat loss per unit surface 

 is much the same in most animals is regarded as a coincidence due 

 to a curiously exact concordance between surface and active proto- 

 plasmic mass, due perhaps to the fact that both of them have a 

 regular relation with the weight in normal cases. As for the egg, it 

 does not contain the potential surface of the animal, save indirectly, 

 for it consists of protoplasm capable of a definite metabolic in- 

 tensity, or rather of following a definite curve till it arrives at a 

 definite metabolic intensity, and upon that eventual intensity the 

 eventual surface of the organism will depend. 



The names associated with the first of these two points of view 

 are numerous. Von Bergmann, one of the earliest workers on basal 

 metabolism, advocated it, and in the earlier papers of Rubner it 

 was fully adopted. In France, Richet consistently made it the basis 

 of his opinions on these problems, and recently it has found a very 

 vigorous defender in Terroine. The second of the two points of view 

 was that originally held by Sarrus & Rameaux in 1838, and subse- 

 quently by von Hoesslin; Krogh; Putter; and Pfaundler. Its principal 

 representatives recently have been the American school (Benedict; 

 Lusk; and Boothby & Sandiford), and certain continental workers, 

 such as Noyons; LeBreton; Schaeffer; and Kayser. It is certainly not 

 possible yet to decide which of the two great groups of investigators 



