Propagation and Longevity. 165 



This matter, as bearing on our subject, may well 

 demand a little more attention and illustration. The 

 slightest influence affecting the sexual parts speedily 

 affects the whole body — more especially those por- 

 tions of the body which set forth the signs of sexual 

 desire, appetite, or strength. Haeckel says : 



" Every change in the sexual organs powerfully 

 reacts on the rest of the body ; so, on the other hand, 

 every important change in another part of the body 

 must necessarily more or less react on the sexual 

 organs. This reaction will, however, only in many 

 cases become perceptible in the formation of the off- 

 spring which arises out of the changed generative 

 parts." '■ 



Haeckel also speaks of " certain influences which 

 act upon the male organs of propagation only, and 

 affect the structure of the male descendants ; and, in 

 like manner, other influences, which act upon the 

 female organs of propagation only, and manifest their 

 effects only in the change of structure of the female 

 descendants. This remarkable phenomenon is still 

 very obscure, and has not as yet been properly in- 

 vestigated." t 



There can be no doubt, further, that length of life 

 is largely dependent on certain restrictions, if one 

 may say so, of the sexual indulgence, viewed in 

 certain aspects — that, in fact, the rule with regard to 

 various lower forms of animals, that the moment of 

 reproduction is also the moment of death, in a modi- 

 fied way, still largely prevails through nature. Dr. 

 Ray Lankester has made a great deal of this principle 



* History of Creation, i, p. 247. 

 f History of Creation, i, p. 230. 



