CiACCio^ on the Nerves of the Cornea. 83 
delineated in these drawings are seen lar^-ely nucleated. The 
nuclei in connection with each individual fibre are often 
equal to the fibre itself in widths and at short distances from 
one another. Not one of those large oval or triangular 
bodies often found in connection with the terminal branches 
of the nerves of common sensation can be seen here. It 
appears to me^ therefore, that upon this progressive increase 
of nuclei in motor nerves,, as they approach their termination, 
and on the remarkable diminution of them in sensitive 
nerves, which, besides, are connected at their ultimate dis- 
tribution with peculiar bodies, we can, with some degree of 
reason, establish a fundamental distinction betAveen the 
terminal portions of motor and sensitive nerves. I cannot 
flatter myself that this conclusion will be accepted as an 
unquestionable fact by the generality of observers, because 
more numerous and accurate observations are required for 
establishing beyond any doubt its exactness. For the 
present it is enough for me to have made an attempt to point 
out some peculiarities which are found in motory and sensitive 
nerves respectively at the periphery. I firmly believe that 
when comparative investigations have been more advanced 
than they are at present, we shall find something peculiar 
not only in the termination of the nerves of motion and 
common sensation, but also in that of every nerve of special 
sensation. 
The limiting investment of the nerves of the cornea. 
The primitive fibres, of which the nerves of the cornea 
are composed, as it may be easily observed, are in more or 
less close apposition with one another. This depends upon 
the nerve-fibres being imbedded in a transparent homogenous 
substance, which forms not only a common covering to all 
fibres composing each separate nerve, but also a special one 
to each single fibre. The nerves in their ultimate ramifica- 
tions are only separated from the adjacent parts by this 
material. According to Dr. Beale, the presence of this 
transparent substance is owing to the changes the nerves are 
continually undergoing during life, and undoubtedly he has 
brought forward a sufficient amount of evidence in favour of 
this view. Notwithstanding, I feel inclined to consider the 
above-mentioned material as a peculiar form of connective 
tissue, produced by a special kind of nuclei. Of these nuclei 
I have already spoken, and have stated the reasons why they 
are to be regarded as different from the nuclei connected 
with the nerve- fibres. I believe that this form of connective 
