HUMAN WORMS. il5 



S. When worms have once been developed in 

 the human body, they take effect and increase, and 

 are nourished by the elements of our system, (doubt- 

 less by the most appropriate,) and they acquire a 

 larger size than those of the same species which 

 remain in the body of other animals, notwithstand- 

 ing the diversity of figure, since naturalists have 

 not yet been able to affirm a characteristic differ- 

 ence between them. (83) 



It seems to be already proved, by an attentive 

 examination of the rudiments, or first forms, of 

 worms, whether human, or those of other animals, 

 and perhaps also those of the earth, that they are 

 formed and organized from the same matter, and 

 that they exhibit a structure more or less uni- 

 form.(84) It is therefore natural that if these 

 worms have acquired life in the human body, that 

 they should grow there, and perish when discharg- 

 ed from it ; but they can live in places where oth- 

 er beings would be destroyed or digested. 



It is however demonstrated that the worms of 

 other animals, introduced into our bodies,(85) if 

 they do not multiply, like those proper to the hu- 

 man system, certainly live there and increase in 

 size. 



6. Finally, worms, being foreign to the human 

 body, do not multiply or generate in it, except 

 when it is predisposed to the asthenic diathesis, or 

 when asthenia actually exists. It appears that 

 Block has advanced a proposition too general in 

 wishing to prove that worms are not always the 



