672 INTRODUCTORY LECTURE OF PROFESSOR SIMONDS 
tions of our patients under the separate systems they are found 
to attack, such as the digestive, the respiratory, the circulatory, 
&c. The observations it will be my duty to make to you will 
have reference, in this my first course, principally to cattle ; but, 
when speaking of any one of their diseases, your attention will be 
directed to the same affection should it be known to exist either 
in the sheep, the pig, or the dog. The diseases to which any of 
these animals are apparently more especially exposed — such for 
instance as rot in sheep, distemper in dogs, scrofula in pigs — 
will form subject matter for our consideration, separately and 
distinctly from the plan which I purpose to pursue. 
Animals have been divided by zoologists into classes, orders, 
families, genera, &c. Those of which I shall have to speak are 
comprised in that grand division called Vertebrata, by which 
term we understand that the brain is inclosed in a bony case, 
the skull or cranium ; and that a prolongation of it, called the 
spinal marrow, is continued through and protected by the bones 
forming the vertebras of the neck, back, loins, &c. They like- 
wise all belong to the class mammalia, that is, they possess 
mammae or teats for the purpose of suckling their young. This 
division and class it will be seen must comprise a very consider- 
able number of animals differing in their habits, their characters, 
the nature of their food, or their use to man. 
For the purpose of still more simplifying and more perfectly 
arranging the great variety of animals abounding on the earth, 
whether domesticated and rendered serviceable to us, or still en- 
joying all their native freedom, it is necessary that subdivisions 
to a much greater extent should be made. These are effected 
with reference either to their feet, their teeth, the internal arrange- 
ments of their digestive organs, or many other varieties of or- 
ganization, but of which it is now unnecessary for me to speak : 
I therefore shall at once proceed to give the zoological position 
of each of our patients. 
You will not have forgotten that all of them are included in 
the division and class of which I have spoken, namely, the 
division vertebrata, the class mammalia. The ox, according to 
Cuvier, belongs to the order ruminantia, implying that it rumi- 
nates or chews its cud or food a second time, and has incisor 
teeth only in its lower jaw, opposed to a hard cushion or pad in 
the upper jaw; — the tribe bovidae; — the genus bos; — and the 
sub-genus bos taurus, or domesticated ox. 
The sheep likewise belongs to the order ruminantia, but its 
structure and habits prevent its agreeing in description to a farther 
extent with the ox : the tribe to which it belongs is the capridse, 
the genus ovis, and the sub-genus or variety ovis aries. 
