57 
Insects and Other Parasites Affecting Domestic Animals. 
It is so very common for persons who have devoted no special 
attention to the humbler forms of animal life to include all of the 
minute animal forms under the term Insects , that the Entomologist is 
frequently called upon to give the history, habits and remedies for 
small parasitic animals which do not belong to the Insect class. 
Having frequently received letters of inquiry in reference to insects 
and parasites affecting domestic animals, I have concluded to devote a 
portion of the present report to this subject. 
In order to make clear what I may write on this subject I will 
first call attention to some generalizations respecting the arrangement 
and classification of the lower groups of animals, including those 
which we shall have occasion to mention. , • 
Mammals, or such animals as man, the horse, cattle, hogs, sheep, 
dogs, cats, etc., are subject to the attacks of a large number of minute 
animals belonging to the great sub-kingdom Articulata , or articulate 
animals. By some recent authorities this large group has been divided 
into two or three sub-kingdoms, but for present purposes the older 
arrangement will suffice, although confessedly somewhat defective. 
The sub-kingdom Articulata is generally defined as that division of 
the animal kingdom embracing all animals which have the body 
made-up of a series of rings or joints, with the skeleton or harder 
parts'external; the nervous system chiefly on the ventral side. This 
definition, although applying generally, is subject to many exceptions; 
as many of the species included present no apparent rings or seg¬ 
ments in the body; in some the nervous system appears to be almost 
or entirely wanting. We can perhaps designate the group more sat¬ 
isfactorily to the general reader by saying that it includes all such 
animals as insects, centipedes, spiders, ticks, mites, lobsters, craw¬ 
fishes, shrimps, leeches, earth-worms, tape-worms and other intestinal 
worms. 
As will be seen from this list, it embraces a vast number of differ¬ 
ent kinds or species of small animals; more, perhaps, than all the 
other divisions of the animal kingdom combined. Although some of 
the subdivisions present considerable difficulty in attempting to classi¬ 
fy them by distinct characters, and place them in proper positions in 
relation to each other, yet naturalists, after much study, have succeed¬ 
ed in arranging them in a manner generally acceptable to scientists. 
The arrangement which we here present is the one most generally ' 
adopted at the present day. 
