PRIMITIVE NERVE FIBRES AFTER SECTION. 
425 
power of moving the tongue, diminished sensibility, generally very slight on the 
divided side, and symptoms indicative of some disturbance of the nutritive functions. 
The diminution of motor power is very slight, as is evident by the almost molecular 
tremor which still exists in any part irritated, and by the capability of retracting the 
tongue. The loss of sensation, which is also very slight, arises from the section of a 
few sensitive filaments which are contained in the glossopharyngeal nerve, and are 
distributed principally about the tubercular extremities. The lesions of nutrition and 
circulation on the side of the division are very variable and uncertain. Sometimes 
that half is oedematous, particularly towards the tubercle. Sometimes the papillae 
are much injected and congested, while in other cases this side is more pale than 
the other. In many instances no difference can be detected between the two sides, 
until the organ has been slightly irritated, when on the divided side the vessels, and 
especially those of the fungiform papillae, become congested and of a deeper red than 
on the other. Some of these differences probably arise from causes indepehdent of 
the nervous lesion, as the v^essels of the tongue which accompany these nerves are 
doubtless injured in some of the experiments. 
During the first two or three days after section, no alteration in the texture and 
transparency of the tubes of the papillary nerves can be detected. Generally, at 
the end of the third and fourth day, we detect the first alteration by a slightly 
turbid or coagulated appearance of the medulla, which no longer appears completely 
to fill the tubular membrane, which does not appear to be affected. These alterations 
of the medulla are best seen in a fragment to which a little distilled water has been 
added to render it more transparent. When examined twenty-four hours after death, 
the diflference between these and the nerves on the healthy side is still more evi- 
dent. Commencing decomposition on the healthy side causes the nerve-tubes to 
swell considerably, so as to attain nearly double their ordinary size. On the divided 
side the disorganized nerve retains nearly the same size and appearance as when 
fresh. Caustic potash, which dissolves all the tissues except the nerves, renders the 
altered nerves more transparent, and consequently the morphological changes are less 
apparent. Nevertheless, by comparative experiments made simultaneously, we may 
still detect a difference between the nerves of the two sides. In some cases, in about 
three or four days after section, I have traced the turbid state of the nerve from the 
fungiform papillae into branches containing forty or fifty tubes, where it did not ap- 
pear to terminate, but where the opacity of the nerve prevented my observing it any 
further. About five or six days after section, the alteration of the nerve-tubes in the 
papillae has become much more distinct, by a kind of coagulation or curdling of the 
medulla into separate particles of various sizes. Sometimes the coagulated particles 
have an uneven spongy appearance, as if the component parts of the medulla, ^. e. 
the white substance and the axis cylinder, were mixed together. Often they appear 
merely like separated particles of the medulla, such as are frequently effused from the 
ends of a divided nerve, and present the double contour and the central nucleus cha- 
MDCCCL. 3 I 
