XVII THE METHOD OF ORGANIC EVOLUTION 375 



ber of individuals presenting these discontinuous variations, 

 we may therefore draw an important conclusion which 

 has hitherto been overlooked. It is, that not only do 

 such variations afford no support to the theory of a 

 special " organic stability " capable of producing races, 

 species, and even genera, without any aid from natural 

 selection, but they furnish a strong, if not conclusive, 

 argument against it, since any which did possess such 

 exceptional stability, and were in no degree injurious, 

 would long since have become equal in numbers to the 

 type of the species. 



Laws of Growth, Importance of. 



A few words are here necessary as to the very common 

 misconception that extreme Darwinians do not recognise 

 the importance of the organism itself and of its laws of 

 growth and development, in the process of evolution. 

 For myself, I may say that no one can be more profoundly 

 impressed by the vast range, by the complexity, by the 

 mystery, by the marvellous power of the laws and pro- 

 perties of organised matter, which constitute the very 

 foundation of all life, and which alone render possible its 

 countless manifestations in the animal and vegetable 

 worlds ; while those who have read Weissmann's account 

 of the complex processes of development of sperm and 

 germ cells, in his volume on The Germ Plasm, must feel 

 sure that he, at all events, can have no inadequate con- 

 ception of their importance. 



What Darwinians deny is — as I understand the ques- 

 tion — that these laws themselves serve to keep the 

 completed organism in close adaptation to the fluctuating 



From this law it follows that, as varieties are usually very much less 

 numerous than the species, this must be due to one of the following 

 causes : either ( 1 ) the variety has but recently originated, and has not had 

 time to increase ; or (2) the variety has ceased to be produced by the 

 species ; or (3) it does not reproduce its like so completely as does the 

 species ; or (4) it is disadvantageous to the species. The first two 

 suppositions are improbable, and can only account for a very small 

 proportion of the varieties which are greatly inferior in numbers to the 

 species; the other two are antagonistic to any special "organic 

 stabilit}'^," which must, therefore in the great majority of cases be 

 rejected as being both unproven and also opposed to the facts. 



