Concurrence and Recapitulation 191 



through processes like those of cm" ; cm" in turn through 

 processes like those in cm' ; and so on indefinitely back to 

 the ancestors of cm. The entire series will then be re- 

 flected, apart from modifying agencies, in cm'" . 



But now referring to the diagram for orthoplasy, we read 

 the facts the other way. If the variation v is to be effec- 

 tive as coincident or concurrent with the modification a, 

 then the processes cm 1 which lead up to v are most reason- 

 ably the same as cm which lead up to a. So the processes 

 cm" should be expected to repeat those of cm' , those of cm'" 

 those of cm" ', etc., each meeting the requirement made upon 

 it of affording continued support to concurrence with the 

 continued accommodation processes a', a", a'", etc. 



It may be said that this extended way of producing an 

 individual, by development through a series of stages, is 

 cumbersome, and that it would be better that it should pro- 

 ceed direct to the adult adaptations by the shortest possible 

 route. Yet, while maintaining that the scientific problem 

 is to ask how development does proceed, not how it migJit 

 proceed, it may be said that it is, indeed, directly in the 

 way of meeting such a theoretical criticism that we find all 

 the abbreviations, ' short-cuts,' omitted stages, etc., which 

 individual embryos actually show the adaptations away 

 from exact recapitulation of which recent discussions have 

 made much. 1 The present writer has suggested 2 that, like 

 everything else, the development of the individual must 

 be subject to variations and such variations would be in 

 turn subject to natural selection. Natural selection would 

 operate wherever the recapitulation process was not the best 



1 For example, those of Sedgwick, Quart. Journ. of Microscop, Science, 

 April, 1894, and Cunningham, Science Progress, I., N.S., p. 483. 



2 Mental Development, 1st ed., p. 32; see also Diet, of Philos. and Psychol., 

 art. ' Recapitulation.' 



