concerning the Reproduction of Nerves . 199 
tory in its result ; for there would still remain room for oppo- 
site opinions : and while some would argue that these anas- 
tomosing filaments were become evidently enlarged, others 
would contend that they had not suffered the slightest change. 
Now, I have already expressed my distrust of those deci- 
sions which are founded on an appeal to the eye, seeing that 
anatomy has yet to explain by what mechanism or structure 
these organs perform their office ; and because I have fre- 
quently heard opposite opinions on my own preparations. I 
therefore prefer an appeal to the functions of these parts, and 
inquire whether, in the experiment in which the dog survived 
the division of the second nerve of the eighth pair after an in- 
terval of six weeks, it was effected by the reproduction of the 
first divided nerve, or in another way ? 
There are only two possible answers to such a question 
these are, that either the functions of the stomach, larynx, &c. 
were carried on by anastomosing nerves ; or that the united 
nerves had recovered their original importance. 
If the first be contended for, this consequence ought to en- 
sue, (viz.) that the eighth pair should now be entirely useless, 
and both of them may be divided a second time, without in- 
juring any of the functions of the animal. 
If the last be granted, it must of necessity follow, that the 
medium of union possessed the same properties as the original 
nerve. 
I have now circumscribed the field of inquiry, and have 
drawn the question into so narrow a compass, that it is in the 
power of a single experiment to prove either the affirmative or 
negative. If now the eighth pair be divided a second time in 
immediate succession, and the animal sustain it with' impu- 
