HUMAN WORMS. iOl 



the male without any preceding copulation : others 

 propagate by the union of the two sexes ;{7) while 

 a third kind fecundate themselves like the tae- 

 niae. (8) See the first Lecture, 



These observations which have been many 

 times repeated and verified by approved writers, 

 leave no doubt of their correctness ; they are di- 

 rectly opposed to the equivocal generation admit- 

 ted by various naturalists as a cause of the origin 

 of our w,orras.(9) 



We readily agree that the simplicity of the 

 structure of worms should exempt them from the 

 ordinary laws, relative to the functions of their 

 life. 



It would however be improper to attribute their 

 birih to some more simple combinations, which 

 some persons have supposed they have seen by 

 means of the microscope, (10) in comparison of oth- 

 er more perfect beings, while the organs which 

 serve for their reproduction arc visible. 



Neither the sex, coition, nor the eggs, nor gen- 

 eration were known to Aristotle and the ancient 

 philosophers, as they are known in our time. In 

 those remote ages, no other generation for imper- 

 fect beiugs was acknowledged, tiian the corruption 

 of substances.(ll) Putrefaction must then have 

 been considered as the cause of the existence of 

 these individuals. 



At this period there was nothing more ingeni- 

 ous than the doctrine of equivocjjl generation, in-. 



