CARNIVORA. 
The pupil of the eye is in some species oval, ’and 
in others circular. It is also capable of much al- 
teration, not only in size, but also in figure, resulting 
from the degree of light acting upon it, and occa- 
sionally from some sudden mental impulse, so as to 
be sometimes round, sometimes oval, and sometimes 
a mere vertical line, in the same animal. 
There are some positions so universally considered 
as true, that no one ever thinks of doubting them ; 
and it is, indeed, on such, that all reasoning must be 
grounded : but we cannot be over scrupulous in ad- 
mitting, or too nice in investigating, any proposition, 
before it is classed with those fundamental axioms 
as self-evident, and therefore not requiring. to be 
demonstrated. 
That the pupils of cats are oval, and that there- 
fore they are enabled to see in the dark, is an as- 
sertion very generally made, and seldom questioned ; 
and some naturalists, observing that the felinae vary 
in this particular among themselves, have separated 
them into diurnal and nocturnal species ; distinguish- 
ing the former by the circular pupil, and the latter 
by that of an oval figure. It may, nevertheless, be 
doubted, whether the shape of the eye-pupil be at all 
connected with the extent of the power of vision ; 
the size of it must, in all probability, be materially 
so ; but it does not appear certain, that those animals 
which dilate the iris, so as to elongate the pupil, have 
also the greatest power of contracting the former, 
and consequently of enlarging the latter, more than 
others which have the pupil at all times circular. 
