78 HEREDITY AND SELECTION IN SOCIOLOGY 



of the worker ants have already disappeared in the chrysalis 

 stage, though they appear as rudiments in the larva. Now, since 

 the impregnation of female ants is invariably associated, as in 

 the case of bees, with a nuptial flight in the air, the degenera- 

 tion of the wings cannot have begun until certain female ants 

 became sterile workers in which no nuptial flight could take 

 place. 



From all the facts at present known to us, we may conclude 

 that the disappearance of useless organs follows certain laws. 

 We are still unable to give a precise definition of these laws 

 or of their mechanical basis ; but observation shows that the 

 degeneration of an organ commences with its final stage of 

 development, continuing in a backward direction till the em- 

 bryonic stage is reached. The necessity for a degeneration 

 working gradually backwards can best be understood from the 

 consequences which degeneration working forwards would entail. 

 It would be impossible for any organ or part of an organ to be 

 suddenly and completely removed without causing a profound, 

 and in many cases a fatal, disturbance of the whole develop- 

 mental process ; but there is a minimum derangement of the 

 development when the degeneration affects, in the first instance, 

 the final stage of that organ or part ; and a degeneration in work- 

 ing backwards merely follows the line of least resistance. The 

 further back in the development the degeneration sets in, the 

 greater is the number of subsequent disturbances and disloca- 

 tions of parts. It is as if, in demolishing an edifice, instead of 

 beginning by the removal of the roof, one were to begin by 

 removing the lower stories or the foundation-stone. 



We may note in passing that the biogenetic law of the " re- 

 capitulation of the phylogeny" (or racial evolution) in the 

 ontogeny (or individual development) is entirely in harmony 

 with the determinant theory.^ By the continuity of the germ- 



1 It must be remembered that this biogenetic law is not absolute. A 

 distinction must be made between, palingenesis — simple, though abbre- 



