422 MIND IN EVOLUTION CHAP. 



of fish, we are for the most part reckoning unfertilised 

 ova, vast quantities of which in fact miss fertilisation. 

 In the higher classes we are reckoning either fertilised 

 eggs or living young. But when all deductions are made, 

 enough seems to remain to justify the general truth of 

 Mr. Herbert Spencer's view that fertility and high 

 individual development in the main tend to vary 

 inversely. 



..." Individuation and Genesis are necessarily antagonistic. 

 Grouping under the word Individuation all processes by which 

 individual life is completed and maintained ; and enlarging the 

 meaning of the word Genesis so as to include all processes aiding 

 the formation and perfecting of new individuals ; we see that the 

 two are fundamentally opposed. Assuming other things to 

 remain the same assuming that environing conditions as to 

 climate, food, enemies, &c., continue constant ; then, inevitably, 

 every higher degree of individual evolution is followed by a 

 lower degree of race-multiplication, and vice versa. Pro- 

 gress in bulk, complexity, or activity, involves retrogress in 

 fertility ; and progress in fertility involves retrogress in bulk, 

 complexity, or activity. 



This statement needs a slight qualification. For reasons to be 

 hereafter assigned, the relation described is never completely main- 

 tained ; and in the small departure from it, we shall find a 

 remarkable self-acting tendency to further the supremacy of 

 the most-developed types. Here, however, this hint must 

 suffice." 1 . . . 



There are doubtless many great deviations from the 

 general tendency. One species may be more preyed upon 

 than another of no higher organisation. If so it must 

 either be more fertile in order to maintain its numbers, or 

 its numbers must fall till they reach a point compatible 

 with greater security. Again, there are countless devices 

 for protection which do not imply an advance, and may 

 even involve retrogression in general development. Such, 

 I imagine, are the hard outer shell of the tortoise, the 

 disagreeable taste of certain insects, and the " protective 

 mimicry " of others. The point is that with all the 

 ^fluctuations due to these causes we find upon the whole a 

 gradual diminution in fertility as we pass from the lowest 

 organisation to the highest. 



1 Op. dt Vol. II. p 429 



