240 



ANIMAL PAKASITES AND MESSMATES. 



sinus of the Eustachian tube. We collected a large bottle 

 full from a single porpoise around its internal ear. 

 When we consider the prodigious number of these 

 creatures, may we not suppose that they are able to 

 multiply in the organs which they occupy, as well as 

 migrate to infest other individuals. 



Different generic and specific names have been given 

 to these Strongyli. A round worm found in the intestines 

 of the dog, the Strongi/lus trigonocephalus, lives at first 

 in damp earth or mud like 

 the rhabdites in general ; 

 it then passes into the 

 dog, and there becomes a 

 sexual Strongylus. It is 

 possible that there are 

 others in the same cate- 

 gory. 



The Ascaris lumhnco' 

 ides is a large round worm 

 which attains the size of 

 a quill pen, and which is 

 commonly found in the 

 stomach or the lesser in- 

 testines of children when 

 in good health. Aristotle 

 was acquainted with it. 

 It has been observed 

 throughout Europe, in 

 Central Africa, in, Brazil, 

 and Australia. The same species lives in the intestines 

 of the pig; but the Ascaris megalocephalus, which is 

 usually found in the horse, is of a different species. 



Ficf. 07.— Ascaris lumbricoides.— 1, com- 

 plete worm. 2, head, 3, tail of the male, 

 4, middle of the body of female. 



