340 THE BWCOSM08 PARTICULARIZED. 



into its own organs. In the higher animals 

 it is noticeable that bodily growth usually 

 ceases with sexual maturity the Plant turns 

 into the Animal, and adds no more layers. On 

 the other hand even in the lower Vertebrates, 

 such as the fishes, growth in size continues 

 long after their sexual maturity, probably in 

 many cases to the end of life, wherein the 

 backboned animal still resembles the Plant. 



Perhaps the most striking transition be- 

 tween asexual and sexual reproduction is seen 

 in the so-called alternation of generations. 

 For instance the jelly-fish, Bogainvillia 

 ramosa, is on the one hand an asexual polyp 

 which produces by budding the sexed medu- 

 sa?, which in turn produce the asexual polyp; 

 the sexless parent brings forth the sexed off- 

 spring, which now bring forth the sexless 

 grandchild, whose offspring are again sexed. 

 Such is the alteration between the asexual 

 and sexual principle in the same animal, 

 which seems to be struggling out of the Plant, 

 yet ever dropping back into it as regards re- 

 production. Single or uni-parental Genera- 

 tion pushes up for once into double or bi-par- 

 ental Generation, but cannot maintain it with- 

 out a dip backward into its previous life- 

 form, where it rises again. Other kinds of 

 alteration between single and double Genera- 

 tion have been observed (for instance in the 



