TERMINATION OF NERVES OF MAMMALIAN CORNEA. 459 
On the Termination of the Nerves in the Mammalian 
Cornea. By E. Klein, M.D., F.R.S., Lecturer on 
Histology at St. Bartholomew’s Medical School. (With 
Plate XXXVII.) 
There is hardly an organ in which the distrihution of 
the fine nerves can be so easily observed as in the cornea, 
thanks to the invaluable discovery of Cohnheim of staining 
the organ with chloride of gold. Since his publication, 
November, 1866, On the Termination of the Sensory Nerves 
in the Cornea,” in ^ Virchow’s Archiv,’ vol. xxviii, a very great 
number of observations on the same subject have been pub- 
lished, all of which have been obtained by Cohnheim’s 
method of chloride of gold. 
On a perusal of all these publications, one arrives at 
the remarkable conclusion that, notwithstanding the excel- 
lence of the method, notwithstanding the distinctness with 
which the final nerves are traceable in all parts of the 
cornea, notwithstanding the great transparency and rela- 
tively simple structure of this organ, notwithstanding the 
absence in it of a variety of structures, such as glands, 
blood-vessels, &c., capable of materially interfering with the 
observation of the fine nerves — notwithstanding all this, there 
exists the greatest variety of opinion as to the termination of 
the fine nerves. 
The arrangement of the microscopically coarse nerve 
branches in the cornea of the frog and mammal were 
understood before the use of the gold method, thanks 
to the researches of Saemisch, Arnold, and Hoyer; and after 
the gold method the observations of Cohnheim, Kolliker, 
Hoyer, His, Waldeyer, and others have, one might almost 
say, been exhaustive on the same, viz. the arrangement of 
the coarser branches ; it is the finer and finest fibres whose 
termination, nay, even whose distribution and arrangement 
is still a matter of discussion. 
The last publication on this subject is by Izquierdo, 
(‘ Beitrage zur Kenntniss der Endigung der sensiblen 
Nerven,’ Inaugural Dissertation, Strassburg, 1879) and by 
Waldeyer (Llrchiv f. mikrosk. Anatom.,’ xvii, p. 367), 
chiefiy relying on Izquierdo’s researches carried out under his 
(Waldeyer’s) direction. They are to the effect that the fine 
nerves entering the anterior epithelium of the cornea termi- 
nate in tlie suporfn-ial lay«us, in the manner described by 
