Internal Parasites. : 225 
sanguinolenta—the blood-red species—which usually occu- 
pies small tumours in the mucous lining of the stomach. 
“The three-corner-headed strongle (Dochmius trigono- 
cephalus) infests the intestinal canal. The wrinkled thread- 
worm (Zvichosoma plica) gains access to the bladder. The 
whip-worm of the dog ( Trzcocephalus depressiusculus) inhabits 
the cecum. The spiral flesh worm (Trichina spiralis) has 
frequently been reared both in the intestines and muscles 
by experiment. 
“ The blood-infesting thread-worm of Grube and Dela- 
fond (F2larza hematica) is probably a distinct species ; and 
the same may possibly be said of Gescheidt’s small 
nematode (/ilarza trispinulosa), discovered in the eye. 
There are also the small thread-worms (/2/aria hepatica) 
found by Mr. T. Mather, V.S., in the liver-ducts and 
substance of the gland, as well as in cysts within the walls 
of the intestines. 
“Lastly, there is another canine hamatozoon, the males, 
females, and embryos of which, according to Professor 
Leisering, occur in the venous blood of certain parts of the 
body of the dog (Hematozoon subulatum).” . 
Another, one of the most difficult to eradicate, and 
perhaps, as Youatt observes, “the most injurious of the 
intestinal worms,” is the tenia, or tapeworm. With regard 
to this species, Dr. Cobbold remarks : “ Although the lum- 
bricoid worms of the dog constitute an important section 
of the canine parasites, the practical interest attaching to 
them is scarcely so great as that which appertains to the 
tapeworms. If, on the one hand, it be allowed that the 
canine cestodes are not so numerous as the nematodes, it 
must, on the other hand, be admitted that (as regards 
public health,* and the propagation of parasitic diseases 
* Tn the first report of the medical officer of the Privy Counc 1, Mr 
Gamgee observes: “There is no doubt that eggs of the tapeworm, de- 
veloped from Cystzcercus tenuicollzs in the intestines of the dog, will 
produce the hydatid in the mesentery and liver of human beings, as it 
