THE VETERINARIAN AS A NATURALIST. 
333 
tulatus, sometimes found in the digestive canal of various her- 
bivora. 
( 3 ) haplococcus reticulatus, a parasite of the muscular 
tissues of the hog, and 
(4) Several kinds of aspergillus, “ moulds,” belonging to the 
perisperiacae, which may develop in the air-passages of birds 
and of some mammals. There are of course, others, but the above 
will suffice, as we have not the time for more than passing refer¬ 
ence. 
Of the protozoa, only three classes contain parasites of the do¬ 
mesticated animals. These are the amoeba, sporozoa, and infu¬ 
soria. Of the first of these is the /‘amoeba parasitica,” which 
lias been discovered in ulcers in the lips and feet of sheep. The 
coccidia and the sarcosporidise, belonging to the psorospermise, 
are the principal representatives of the sporozoa affecting the 
work of the veterinarian. The coccidia chiefly infest the di¬ 
gestive canal, the sarcosporidise being found exclusively in 
muscular tissue. 
The infusoria found in the domestic animals, and observed 
more particularly in the alimentary tract or its accessories, be¬ 
long to the sub-class flagellata or ciliata. We have also'the 
pyrosma bigeminum ” of tick fever which is a protozoon. 
The second section of the zooparasites requiring our atten¬ 
tion : the entozoa, vermes, or helminths, is made up of an im 
mense collection, and are usually divided into two classes, viz.: 
the plathelminths, with bodies generally flat ; and the nemathel- 
minths, whose bodies are nearly cylindrical. 
The plathelminths comprise the following three orders : 
Cestodes, trematodes, and turbellaries. The first two, however, 
are limited to a parasitic existence. To the first of these belong 
the taeniae or tapes, and their life-histories form an interesting 
study from the standpoint of the naturalist as well as that of the 
pathologist. In the adult stage they exist in the intestines of 
the higher animals, but in the immature stages they undergo a 
certain number of metamorphoses and migrations, which are 
often brought about in the most diverse organs of different hosts. 
