288 Remarks on a Work entitled 
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the brain.” It is moreover stated, that there is a direct connexion 
between the temperature of animals in general and the amount of 
red globules in their blood, and that there is as marked a con- 
nexion between the amount of sensibility and of animal heat as 
there is between the latter and the amount of cruorine in the 
blood ; from all which it is inferred, that as sensibility is in pro- 
portion to the size and quality of brain, and the amount of red 
globules in the blood, a creature which has no brain and “ no red 
blood” (just now it was “ altogether without blood’) should be 
devoid of sensibility. 
There are also, it is stated, several points in which the physio- 
logy of insects resembles that of plants rather than that of animals, 
viz. perpetuation and superfcetation of species, longevity if the 
functions of generation be delayed, evolution of heat under certain 
circumstances, the generation of spontaneous light, and the opera- 
tion of poisons. 
This, then, is an outline of the theory that insects are devoid of 
sensation. The proofs adduced are the following :— 
Toucu. 
In the higher animals, ‘“ the particular senses are so far inde= 
pendent of the diffused sensibility of the organs which administer 
to them, that the sense, or particular office of the nerve, may be 
lost, while the sensibility of the external structure remains. In 
amaurosis, or extinction of the visual power, the general sensibility 
of the retina is retained; the ear which has lost its hearing may 
ache; both taste and smell have been nearly abolished, without in 
the least impairing the common sensibility of the mucous mem- 
brane of the mouth and nose. But the reverse will by no means 
be found to follow: we have no experience of the ear, the eye, the 
palate or the nostril carrying on their peculiar functions after the 
general sensibility of the tissues has been extinguished. In touch 
we have positive experience to the contrary; a skin on which 
stimuli would fail to act,—a skin which could neither smart, ache, 
nor be tickled, ceases to be the organ of touch, as we see it ex- 
emplified in the effects of intense cold, which, by depriving the 
surface of that blood which supports and vivifies its subtle organi- 
zation, numbs its general sensibility, and at the same time paralyses 
the particular sense, while an increasing warmth communicates to 
the over-sensible skin an increased nicety in the fulfilment of its 
office. If, then, an highly organized tissue can, through the 
withdrawal of some of the conditions of its healthy state, become 
utterly unserviceable as a means of distinguishing the surfaces of 
