276 THE REV. THEODORE WOOD, F.E.S., ON 
Mr. W. F. Kirsy, F.L.S., F.E.S., &c.—It has always seemed to 
me that pain is simply calculated to effect a useful end. I think 
IT am correct in saying that it is generally distributed in such a 
manner as to be a warning when an injury is inflicted, or else to 
prevent worse injury. Consequently, when a sudden injury, that 
cannot be foreseen and provided for in the ordinary course of 
events, is inflicted, pain sometimes ceases to operate, being no 
longer useful. As to insects, I need hardly go into that question, 
which the Lecturer has treated so well; but I may say, in the case 
of beetles, that they will sometimes remain alive for many months 
with a pin through them, and apparently enjoy themselves. It 
has been recorded that one beetle remained alive for upwards of 
two years in this state. A caterpillar will certainly wince at 
times when attacked by ichneumons, but whether that is from pain, 
fear, or reflex action, is, of course, open to doubt. I remember 
reading a story—lI think by Professor Jesse—of a pike that was 
thrown out of the water and injured its head and appeared to be 
in great pain. A gentleman, who was a naturalist, going by, 
relieved it and returned it to the water, and the pike always 
recognised him when he came back to the same place after- 
wards. 
With regard to the cases of human susceptibility to pain that 
have been adduced, I may say that it frequently happens that when 
operations have been performed under chloroform, or under the 
inflnence of mesmerism (or as if is now improperly called, 
hypnotism), patients have often been unconscious of it until they 
have actually seen the wound, and only then have they declared 
that they felt pain. There are several instances of this kind on 
record. 
The CuairmMaN.—Before the Author replies, perhaps I may 
remind you that if you take away the capacity for feeling pain, you 
take away tnat for feeling pleasure also; for pain is often the 
excess of that which in more moderate degree gives pleasure. If 
invertebrates feel no pain, probably they feel little pleasure, for 
the mere reflex movement and response to stimuli does not neces- 
sarily imply either pleasurable or painful sensations. 
The AurHor.—I will begin by noticing some of Dr. Walker’s 
statements as to insects and animals. 
First as to the Cerwra vinula caterpillar. How do yon prove 
that it is capable of feeling pain? Is not its action simply 
