54 THE PRINCIPLES OF HEREDITY 



regressions, recapitulation, no matter how obscured to our eyes 

 by the complexity of the process, must still have occurred. 

 Those biologists who, deceived by the unlikeness of the 

 embryo during the different stages of its development to the 

 lower animals which were its prototypes in the life-history, 

 have declared that the development of the individual is not a 

 recapitulation of the life -history of the race, can have never 

 adequately considered the problem, or else are guilty of exces- 

 sively careless and inaccurate language. If evolution has been 

 an actuality, as we know it has, and if each individual during 

 growth follows in the developmental footsteps of his parent, 

 then the recapitulation of the life-history of the race in the 

 development of every individual belonging to it is inevitable. 

 Otherwise we must suppose that at some period of the life- 

 history a break occurred, an individual, or rather a whole 

 generation of individuals, gave origin to monstrous and even 

 miraculous offspring. The parent did not reproduce his like ; 

 the child did not follow in the developmental footsteps of the 

 parent ; but an individual of one species reproduced an indi- 

 vidual of quite another species. It is as if a fish had given 

 birth to a dog, or a bird to a man. Monstrous births are not 

 unknown to medical men, but none so monstrous as this. 

 Moreover the monsters we know perish. They are not adapted 

 to their environment. Adaptation arises only through a 

 gradual process of evolution. But this monster who is 

 supposed to have broken the orderly recapitulation of the 

 life-history must necessarily have been adapted to his environ- 

 ment since he survived and begat descendants descendants 

 who, it is to be presumed, did not follow his example, but, 

 taking up the ancient tradition, recapitulated his development. 

 We have no choice, no alternative, but to believe in a 

 miraculous monster many miraculous monsters or to believe 

 that the development of every individual is a recapitulation 

 of the life-history of the race. " Under a scientific point of 

 view, and as leading to further investigation, but little advan- 

 tage is gained by believing that new forms are suddenly 

 developed in an inexplicable manner from old and widely 

 different forms, over the old belief in the creation of species 

 from the dust of the earth/' 1 



91. But to say that there is recapitulation is one thing. 

 To say that there is accurate and complete recapitulation is 

 quite another thing. It is obvious that in no instance is the 

 recapitulation accurate and complete. In no instance does an 

 individual reproduce all his ancestors exactly. Thus presum- 

 1 The Origin of Species, p. 662. 



