MINUTE ANATOMY OF THE PAPILLAE OF THE FEQG’S TONGUE. 
451 
The material marked a (Plate XXI. fig. 2) is a continuation of the nervous structure 
or tissue, while the matter marked b bears the same relation to this as the so-called 
nucleus of a nerve bears to its fibre, of an epithelial cell to its wall. If this be so, the 
matter which is freely exposed at the very summit of the papilla is -at least structurally 
continuous with nerve-tissue, if it is not to be regarded as nerve itself. My own opinion 
is that it is just as much nerve-tissue as a fine nerve-fibre is nerve-tissue, or the caudate 
process of a nerve-cell is nerve-tissue. The formed matter is produced by the large 
masses of germinal matter which are so very numerous, just as the formed matter of a 
central nerve-cell results from changes occurring in its germinal matter. 
It may not be out of place here to consider how the elaborate organ connected with 
the bundle of nerve-fibres of the papilla may act during life. As already stated, the 
free surface is uneven, and the arrangement is such that there are many elevations pro- 
jecting, like fibres, by slightly varying distances, from the general surface. Now from 
the intricate interlacement of the nerve-fibres in the summit of a papilla, as well as at 
the point between this and the peculiar organ (Plate XXI. fig. 3, b), it is obvious that 
a fibre given off from one coming from the extreme left of the papilla, for example, may 
be situated a very short distance from a fibre coming from the opposite side. Any 
object, therefore, which connects the exposed projections would produce a temporary 
disturbance in the nerve-currents which are traversing these fibres, and this alteration 
in the current would of course produce a change in the cell or cells which form part 
of the same circuit in the nerve-centre. Any strong pressure would influence all the 
fibres distributed to this delicate nervous organ. 
The supposed mode of action is explained by the plan (Plate XXI. fig. 4). 
Nerve-fibres ramifying upon the capillary vessels , in the connective tissue , 
and upon the muscular fibres. 
Many of the so-called connective-tissue corpuscles, with their anastomosing processes 
or “ tubes” are really nerve-nuclei and very fine pale nerve-fibres, as has already been 
shown in observations upon the frog’s bladder. In the tongue I have followed these 
fine fibres in very many specimens. They can only be seen and traced in specimens 
prepared in syrup, glycerine, or other viscid medium miscible in all proportions with 
water. 
In Plate XXI. fig. 1 ,f and in fig. 8, one of these fine branches, coming off from 
a bundle of dark-bordered fibres, is represented. Now, if examined by a low power, 
this might be mistaken for a fibre of connective tissue ; but it really consists of several 
very fine fibres, which in their arrangement exhibit the same peculiarities observed in 
nerves ramifying in larger trunks (Plate XXII. figs. 20, 23). The fine branches divide 
and subdivide, and the delicate fibres resulting from their division can be followed for a 
very long distance. The finest are composed of several finer fibres, and they form 
networks or plexuses, the meshes of which vary much in size. 
The branches which are distributed around the capillaries, in the connective tissue, 
mdccclxv. 3 Q 
