*Tir 



ORGANIC EVOLUTION — THE FACTORS ( I 



which did uot vary favourably in this respect perishing 

 with their hives in consequence of competition and 

 leaving no descendants. Now the variations in the 

 queens which caused them to produce better and better 

 workers cannot have been acquired, for queens do not 

 work, and the evolution of workers can therefore have 

 been due only to the accumulation of inborn variations 

 in the successive queens. It is true that the actual 

 anatomical structure and the instincts of the queens 

 and workers, one or both, are to be regarded in great 

 measure as acquired variations, since they result largely 

 from the kind of food supplied to the larvae, but these 

 acquired variations in the workers cannot be transmitted 

 to offspring, for, as I say, they have no offspring. The 

 very power of acquiring them must have resulted from 

 the accumulation of inborn variations. 



The social system and the subdivision of labour 

 among bees (and ants) are so remarkable, that they 

 present perhaps the most extreme examples of evolu- 

 tion to be found in nature, not even excepting that of 

 man. Yet in the face of this we find many Avriters 

 insisting, in cases as simple as that of the evolution of 

 horns, that acquired variations are factors of the evolu- 

 tion, and doing so when, in other strictly analogous 

 cases, they admit that acquired variations can have had 

 no part. For example, Mr. Herbert Spencer says 

 {Princiiolcs of Biology, vol, i. pp. 295-G) — 



" Taking, for instance, the callosities on the knuckles 

 of the Gorilla, which are adapted to its habit of partially 

 supporting itself on its closed hands when moving along 

 the ground, — shall we suppose that these defensive 

 thickenings are produced afresh in each individual by 

 the direct actions, or that they are inherited modifi- 

 cations caused by such direct actions, or that they 

 are wholly due to the natural selection of spontaneous 

 Variations ? This last supposition does not seem a 



