102 ENTOZOA FOUND [N MAN. 



intestines by the act of vomiting, and had lodged in 

 the tonsil ; it was found during a post-mortem 

 examination of a soldier, who died at Fort Pitt ; the 

 left tonsil, in which it was embedded, was much 

 enlarged, and in a gangrenous condition. 



The tricocephali are probably fixed during life to 

 the intestinal walls by their heads, which are thrust 

 into the mucous membrane, 



They exist in persons of all ages ; Wrisberg 

 states that he has seen them in children under two 

 years of age, and they are known to be extremely 

 common in adults. Many writers attest to their 

 great frequency, and Dr. Davaine remarks that in 

 making microscopical examinations of the dejections 

 of a number of persons suffering from various dis- 

 eases, he met with the ova of the tricocephalus in 

 nearly one half of them. 



These worms are usually not very numerous in 

 the same individual, and sometimes only one or two 

 specimens are found ; but in certain affections, and 

 especially in typhoid fever, they are discovered in 

 greater numbers than in other diseases.^ 



This species of entozoon has been observed in all 

 parts of the world ; and especially in France, England, 

 Germany, Egypt, and the United States. 



Its mode of propagation appears to be analogous 

 to that of the Ascaris lumbricoides. The ova, which 

 are expelled with the evacuations, do not become 



^ "Wrisberg affirms that these eutozoa penetrate into the orifices 

 of Peyer's glands, and of the mucous follicles in other parts of 

 the intestines. This statement has been contradicted by some 

 writers ; but, if it be correct, it throws an important light 

 upon certain morbid states of that portion of the intestines in 

 which the tricocephali are found. 



