BIONOMICS 199 



tend towards sluggishness. If in a particular kind of food the 

 extremely inert element Nitrogen is present in undue propor- 

 tions which, no doubt, is the case wherever proteins are too 

 exclusively consumed, this must induce sluggishness and 

 obesity (accumulation of waste matters), giving the appearance 

 of exuberance of growth in many organs and tissues. This 

 exuberance may in the course of several generations lead, 

 though pathogenetically (as we shall see more fully anon), to 

 a huge increase of size a giant race morbidly bred. A race of 

 in-feeders, though really on the path of degeneracy, may thus 

 outstrip its former cross-feeding allies so far as individual size 

 is concerned. The experiment, however, seeing that it results 

 in the loss of symbiotic correspondences and general morbidity, 

 cannot lead to permanent good results, but must on the con- 

 trary conduce to increasing liability to " decompositions " of 

 all kinds, physiological and social. 



Prof. Houssay (Sorbonne) has shown by experiment that 

 to feed fowls on a meat diet, i.e., mainly protein, is to cause 

 extinction of the race in a few generations, although generally 

 and for a time it is quite possible to obtain greater bulk by a 

 change from, a mixed diet to a more purely in-feeding, i.e., 

 proteid diet. 



That, failing sufficient molecular mobility, there is great 

 liability to accumulation of waste matter had not escaped 

 Spencer. This is how he deals with the contingency : 



And now we may clearly see the necessity for that peculiar compo- 

 sition which we find in organic matter. On the one hand, were it not 

 for the extreme molecular mobility possessed by three of its chief 

 elements out of the four; and were it not for the consequently high 

 molecular mobility of their simpler compounds ; there could not be this 

 quick escape of the waste products of organic action ; and there could 

 not be that continuously active change of matter which vitality implies. 

 On the other hand, were it not for the union of these extremely mobile 

 elements into immensely complex compounds, having relatively vast 

 atoms that are made comparatively immobile by their inertia, there 

 could not result that mechanical fixity which prevents the components 

 of living tissue from diffusing away along with the effete matters pro- 

 duced by the decomposition of tissue. 



