AND THE LOWER ANIMALS. 237 



Does it follow from this that all these terms should 

 be erased from scientific terminology ?— No. The 

 words multiplication by buds, offshoots, fission, &c, 

 and those of alternate generation, metagenesis, and 

 digenesis, really express correct ideas and distinct 

 facts. They will be often found useful in giving 

 precision to language, and on that account they should 

 be preserved. But it follows, from what has been 

 said, that each of them must be employed to designate 

 one> and one only, of the special forms under which 

 geneagenesis in its most general condition may present 

 itself. 



Although very well named, this phenomenon is not 

 explained. Moreover, we need not hope to discover 

 the primary cause, at least not for a long while. The 

 utmost we can do is to associate it with other facts 

 already understood, and thus elucidate its real nature. 

 Besides, the naturalists whose writings we have 

 alluded to, have all striven to refer agamic generation 

 to sexual generation, and reproduction by buds to 

 reproduction by ova and by fertilized ova. This 

 we believe to be the main cause of the difficulties they 

 encountered. 



Dr. Carpenter has taken quite another point of view.* 

 According to this English savant, oviparity is an 

 entirely different process from gemmiparity. The 

 first requires the intercommunication of two systems 

 of special and distinct organs; the second is simply 

 "a multiplication of cells in the course of a con- 

 tinuous growth." There may be a few slight differ- 



* " Medico-Chirurgical Keview," 1848. I regret that I am only 

 acquainted with this essay through Professor Owen's comments 

 upon it in his " Parthenogenesis." 



