oct. — dec. 1857.] On Moths and Bees. 



Ill 



by all who have examined these and kindred forms ; and from the 

 researches of Sars, Steenstrup, Siebold, and others, we arrive ^at 

 the conclusion, that, in many of the forms of lower existence, 

 animals produce offspring, which at no one time of their develop- 

 ment resemble their parents ; but which, however, in their turn 

 bring forth a progeny which revert in their form and nature to the 

 parent animal, so that the maternal animal does not meet with its 

 resemblance in its own brood, but in the descendants of the second, 

 third, fourth, or even more remote degrees of generation ; and this 

 has been proved to be the case in many of the Medusae, Claviform 

 Polypes, Salpae, many Entozoa and Aphides ; and, according to 

 the assertions of some naturalists, in all the lower classes of ani- 

 mals ; so much so, that we cannot avoid inferring that many ani- 

 mals described as belonging to distinct species are but the alternate 

 generation of known forms. The phenomena of alternation of 

 generation differ essentially from metamorphic changes ; in meta- 

 morphosis we have changes taken place in the same individual ; 

 while in alternation of generation, or metagenesis, different and 

 many individuals arise and are separated from the parent ; besides, 

 in the course of metagenesis, in many instances metamorphosis 

 also takes place. In metagenesis we observe that in one alterna- 

 tion are produced distinct ovaries and ova ; in the others the de- 

 velopment does not take place from ova, but by a process of gem- 

 mation ; and in the isolated Salphae, a remarkable organ (Stolen 

 jproligerum) has been described, whence are developed the catenat- 

 ed offsprings. 



These facts have gone far to solve a difficulty felt by some op- 

 ponents to the " development theory ;" it has been stated by the 

 ingenious author of the " Vestiges," that if animals have not been 

 developed since the creation, our first parent should have had de- 

 posited in their structure either all the human entozoa or their ova. 

 The phenomena of metagenesis, however, may lead us to infer, 

 that all human entozoa may be but alternate forms of those ani- 

 mals found in other creatures or elsewhere, and this is actually the 

 case with one entozoon (Cysticercus fasciolaris) which in one form 

 is found in the cat, in another in the rat or mouse. In true par- 



