GENESIS. 290 



Eeduced to its lowest terms, we here see the antagonism 

 between that growth of the coherent mass of units which 

 accompanies its physical prosperity, and that incoherence and 

 dispersion of the units which follows unfavourable condi- 

 tions and arrest of growth, and which presently initiates new 

 Plasmodia. 



This antagonism, seen in these incipient Metazoa which 

 show us none of that organization characterizing the Metazoa 

 in general, is everywhere in more or less disguised forms 

 exhibited by them — must necessarily be so if growth of the 

 individual is a process of integration while formation of new 

 individuals is a process of disintegration. And, primarily, it 

 is an implication that whatever furthers the one impedes the 

 other. 



But now while recognizing the truth that nutrition and 

 innutrition (using these words to cover not supply of nutri- 

 ment only but the presence of other influences favourable or 

 unfavourable to the vital processes) primarily determine the 

 alternations of these; we have also to recognize the truth 

 that from the beginning survival of the fittest has been 

 shaping the forms and effects of their antagonism. By in- 

 heritance a physiological habit which modifies the form of 

 the antagonism in a way favourable to the species, will become 

 established. Especially will this be the case where the lives 

 of the individuals have become relatively definite and where 

 special organs have been evolved for casting off reproductive 

 centres. The resulting physiological rhythm may in such 

 cases become so pronounced as greatly to obscure the primi- 

 tive relation. Among plants we see this in the fact that 

 those which have been transferred from one habitat to another 

 having widely different seasons, long continue their original 

 time of flowering, though it is inappropriate to the new cir- 

 cumstances — the reproductive periodicity has become organic. 

 Similarly in each species of higher animal, development of 

 the reproductive organs and maturation of reproductive 

 cells take place at a settled age, whether the conditions have 



