318 THE RECAPITULATION THEORY 



furnish many other cases. A curious instance is 

 afforded by the development of the teeth in mam- 

 mals, if recent suggestions as to the origin of the 

 milk dentition are confirmed, and the milk dentition 

 prove to be a more recent acquisition than the 

 permanent one.* 



s But the most important case in reference to dis- 

 j:ortion in time concerns the reproductive organs. 

 If development were a strict and correct recapitula- 

 tion of ancestral history, then each stage would 

 possess reproductive organs in a mature condition. 

 This is not the case, and it is clearly of the greatest 

 importance that it should not be. It is true that 

 the first commencement of the reproductive organs 

 may_occur_ at a very early stage, or even that the 

 very first step in development may be a division 

 of the egg into somatic and reproductive cells ; and 

 it is possible that, as maintained by Weismann, 

 JJiis latter-condition is a primitive one. Still even 

 in. these jgses the reproductive organs merely com- 

 mence their development at these early stages, and 

 ^la-aot-become functional until the animal is adult. 



<L_Exceptionally in certain animals, and as a 

 normal occurrence in others, precocious maturation 

 of the~1Feproductive organs takes place, and a larval 

 form becomes capable of sexual reproduction. This 

 may lead to arrest of development, either at a late 

 larval period as in the Axolotl, or at successively 



* C/. Thomas Oldfield, " On the Homologies and Succession 

 of the Teeth in the Dasyuridae, with an attempt to trace the 

 history of the evolution of the Mammal and Teeth in general," 

 Phil. Trans. 1887. 



