324 FUNCTIONS AND INSTINCTS. 



are so reduced, that where thousands were seen 

 in summer, in spring scarcely one has survived. 

 Their substance is so soft and gelatinous, that 

 they are easily destroyed ; to compensate this, 

 they are gifted with the extraordinary powers 

 of reproduction above described. God hath so 

 tempered his sentient works, that seeming 

 defects, in one respect, are compensated by 

 redundance in another. 



Having made these observations upon animals 

 of this class, that do not infest man or beast 

 internally, I next turn to those whose office is, 

 in spite of all his care, to make the Lord of the 

 Creation, as well as the whole animal kingdom, 

 not only their constant abode, but also their 

 food. More than twenty of these pestiferous 

 creatures, that attack man, have been enu- 

 merated ; some penetrate into the very seat of 

 thought; 1 others disturb his bile; 2 others cir- 

 culate with the blood in his veins ; 3 others, again, 

 are seated in his kidneys ; 4 others in his muscles ; 5 

 the guinea worm 6 in his cellular tissue: the 

 ovaries of females are infested by another ; T the 

 tape-worms extend themselves, joint by joint, 

 to an enormous length in his intestines ; 8 some 



1 Echinococcus Hominis. 2 Fasciola hepatica. 



3 Linguatula Venarum. 4 Strongylus gigas. 



5 Hydatigera cellulosa. 6 Filaria medinensis. 



7 Linguatula pinguicula. 



8 Tcenia-solium, and Botryocephalus Hominis. 



