ON THE REPRODUCTION OF THE NERVES. 523 
tion of nerves. He found that the ends of a divided nerve really 
united in the course of a few weeks by thin threads which could 
not be dissolved in nitric acid. If he removed part of the sub- 
stance of the nerve, its ends even then united, but the union 
took place slower; for instance, when he removed a line, he found 
that reproduction was effected in three weeks, and when two 
lines, after two months. 
Although from these experiments it might appear that the ques- 
tion was fully settled, we still find some distinguished physiolo- 
gists opposing the idea of the reproduction of nervous substance. 
Thus, for instance, Richerand * states, that he was sufficiently 
decided to adopt the opinion that the nerve was reproduced, but 
that he repeated Haighton’s experiments without success. The 
paralysis, according to this author, which followed the division 
of the nerves, is incurable. Delpechf states the same thing, 
and also denies the reproduction of nerves. MagendieJ also 
affirms, that he frequently repeated Haighton’s experiments ; the 
animals, however, invariably died five days afterwards ; and from 
this he supposes that Haighton must have committed some mis- 
take about the division of the nerve. Owing to these contradic- 
tory statements, Joseph Swan § was induced to repeat all the 
experiments anew. On rabbits he tried twenty, and on dogs 
two, of which the following are the results. After the division 
of a nerve, the extremities, particularly the superior one, became 
thicker and more vascular : coagulable lymph, having the 
appearance of albumen, was poured out, and in a very short 
space of time permeated by bloodvessels. In the course of a 
few days, this coagulable lymph united from both ends, and 
anastomosing vessels were soon formed in it. It gradually ac- 
quired a firmer texture, the number of bloodvessels diminished, 
it shrunk together as in cicatrization, and the separated extre- 
mities approached each other more ; but it was difficult to deter- 
mine when the nerves were capable of again resuming their 
functions. One rabbit recovered itself a little within eight 
* Richerand Nosographie Chirurgicale, tom. ii, 207, 210 . 
+ Delpech Ricis Elementaire des Maladies Chirurgicales. Tom. i, 
p. 173. 
t Magendie’s Journ. Tom. i, No. 2, p. 122. 
§ Swan on the Local Diseases of the Nerves, 
