78 Mr. Home's Description of the Anatomy 
in some birds in a less degree, as in the parrot and the spoon* 
bill; which last bird, in the structure of its beak, bears some 
analogy to this animal. The tentorium is entirely membranous. 
The brain was not in a state to admit of its structure being 
accurately examined ; but it appears to be made up of the same 
parts as those of quadrupeds in general. 
The olfactory nerves are small, and so are the optic nerves ; 
but the fifth pair, which supplies the muscles of the face, are 
uncommonly large. We should be led, from this circumstance, 
to believe that the sensibility of the different parts of the bill is 
very great, and therefore that it answers the purpose of a hand, 
and is capable of nice discrimination in its feeling.* 
The eye is very small, and is nearly spherical : the globe is 
about £ of an inch in diameter ; the cornea r 3 w of an inch in 
diameter. There is a membrana nictitans; and the eyelid is very 
loose upon the eyeball ; it is probably capable of great dilata- 
tion and contraction. 
The organ of smell, in its construction resembles that of other 
quadrupeds, and may be said to consist of two turbinated bones 
in each nostril ; that next the bill is the largest, and has the 
Ion 2: axis in the direction of the nostril ; its external surface is 
very irregular. The posterior one is shorter, projects further 
into the nostril, and is situated transversely, with respect to the 
nostril. As the external openings of the nose are at the end of 
the bill, there is a canal of an unusual length for the air to pass 
through, before it is applied to the immediate organ, unless there 
is an extension of the branches of the olfactory nerve upon the 
linings of the cavity, so as to make it a part of it. The external 
* The same observations were made by Professor Blumenbach, ox Gottingen, 
who first dissected these nerves. 
