''S^ulTilnSSTS^^^ Fungiform Pa^ill^. 11 
The lax tissue beneath the tongue of the frog furnishes a won- 
derful plexus of nerve-fibres, many of them running in the sheath 
of connective tissue, and being separated by very large nuclear 
germinal masses, which I regard as centres of nerve force. Although 
I have in sections of the tongue itself found these large nuclear 
masses (Fig. 10) but rarely; there is an abundance of pale, flattish 
gelatinous-looking fibres, which, whether they should be regarded 
as nerves in the course of further development, or decaying, or as 
belonging entirely to the ganglionic system, must, I think, be 
regarded as uncertain. In this wonderful plexus exceedingly 
delicate nucleated nerves can be traced for considerable distances; 
and many represented as a single fibre, by higher powers, are found 
to be formed of two or more, often twisted, as first noticed by Dr. 
Beale. Sometimes one of the fibres may be seen attached to the 
nucleus at either end, and two or more divergent fibres pass at 
the sides of the nucleus without apparently being in contact, and 
unite again with the single fibre to continue their course. In such 
an arrangement, whatever may be the fact in the single grey nerve- 
fibres, I think we may justly conclude the single fibres here have 
to be composed in their whole course of two or more (Fig. 11). 
In attempts to offer any explanation of the action of the fungi- 
form papillae, supposing them to be the chief seat of taste, it becomes 
necessary to try and settle the preliminary points of structure ; but 
admitting these points are not fixed, still we may be at liberty, 
according to the view taken, to suggest the action of the various 
parts. Suppose a sapid body to be presented to the surface of the 
papillae ; that the substance percolates or dialyses between the outer 
cells which I have regarded as epithelial, and gets to the surface of 
the extremities of the cylinder rods or little tuft, and that a sensuous 
impression, of whatever nature it may be, is at once conveyed to 
and distributed through the plexus beneath, and by it to the divi- 
sional fibres of the dark-bordered nerves in the fungiform cone or 
expansion; by these conveyed to the centre, there to excite an 
impulse or sensation which is recognized ; and by the sympathetic 
returned through the fine nucleated nerve-fibres given to the arteries 
and capilliaries, by which indirectly the secretion of the epithelial 
cells may be temporarily augmented, and a motor impulse conveyed 
to the muscles of the papilla itself ; or to the muscles at the base of 
the tongue, palate, and the larynx, by which the act of swallowing 
is induced ; and this to be repeated as often as the impression lasts, 
or is sufficient to disturb the harmonic balance, — may afibrd a faint 
picture of the actual condition. 
The distinction and action of the several nerves under their 
having employed the highest magnifying powers. The subject undoubtedly wants 
reinvestigation. My own opinions are embodied in this and a paper on Tipula 
crystallina, presented to the Royal Society last year. 
