of a male Rhinoceros, 151 
necting them with the sclerotic coat. It is well known that the 
iris, and also other parts of the body, possess to a great degree 
the power of contraction, without our being able to demon- 
strate muscular fibres ; allowing, therefore, these processes to 
have the common properties of muscles, we shall be better 
enabled to form some idea of their uses. 
It is related by naturalists, that the rhinoceros does not enjoy 
a very quick sight ; and that he can only distinguish objects 
which are placed immediately before him. This notion most pro- 
bably has arisen from the apparent dullness of his eyes, and the 
great difficulty he must meet with in turning the head from side 
to side, encased as the neck is by its strong unyielding cover- 
ings. I conclude, however, that if we should ever become 
acquainted with the natural habits of this animal, his vision 
will be found to be as perfect as that of any other of the same 
class. In the muscles, I have already remarked, that there is no 
difference ; of course, the eye-ball, with those powers, must en- 
joy the common motions. With respect to his ability for seeing 
near objects, it is not probable that nature should have denied 
to this creature, a faculty which has been granted to every other, 
viz. a power of minutely examining their food before it is taken 
into the stomach ; now, as his eyes are placed nearer the mouth 
than in any other quadruped we are yet acquainted with, it is 
but reasonable to suppose, that his powers for accommodating 
vision to very near objects must be equal, if^not superior, to 
theirs. In the easy and natural state of the eye, it is probably so 
adjusted as to view with perspicuity very near objects, requiring 
some change to adapt it for distinguishing distant ones. This 
change, most likely, is effected by the four processes acting con- 
jointly : at their terminations they completely encircle the eye 
