114 



MAMMALIA. 



they keep pace with each other. The respiration of 

 the mammalia is always accompanied by voice of 

 some kind or other , but though in many of them the I 

 organs of voice bear a much closer resemblance to 

 man than those of otherclasses of animals, and especi- 

 ally than those of birds, yet none of the mammalia 

 have ever been taught to articulate, or to imitate 

 sounds, although many birds are capable of being 

 taught to utter words, and to execute pieces of music 

 with very great perfection. This unquestionably does 

 not hapf>en from any inferiority of resources, or what 

 is usually called animal sagacity ; for in these respects 

 the mammalia stand far higher than any other animals. 

 As they do in other respects, so in this, they differ 

 greatly from each other ; but in the whole of them 

 there is an expression in the eye, a readiness in the 

 ear, and an aptitude to take notice of circumstances 

 around them far superior to what is to be found in 

 any of the other classes. They also readily know 

 persons and places, and they understand sounds, and 

 feel pleasure at some, while they are irritated by others. 

 It should seem, therefore, that their inability to imi- 

 tate sounds, and especially articulate sounds, is a 

 matter of organisation merely, and has nothing to do 

 with the system of sensation. Indeed we have some- 

 thing nearly corresponding to this, for the most elo- 

 quent speakers are rarely the most acute or profound 

 thinkers ; and it is at least not proverbial that those 

 who have the sweetest voices have the best under- 

 standings. 



The allocated organs of particular senses are the 

 same in number and in situation, making allowance 

 for differences in the general form of the body, in all 

 the mammalia. The ears are always two in number, 

 farthest backward on the upper or lateral part of the 

 cranium ; but they differ greatly in their develop- 

 ment and their external form, according to the extent 

 to which the animal has occasion for the sense of 

 hearing, and the times and places when that sense is 

 exercised. The eyes follow next in advance ; but 

 their position varies according to the direction in 

 which the animal has most occasion to exercise the 

 sense of sight ; and many circumstances also tend to 

 vary their size, mode of action, and intensity of per- 

 ception. The organs of smell have also their general 

 situation similar in the whole ; and so have the organs 

 of tasting ; though both of these vary much in the 

 degree of their acuteness. What Is usually termed 

 the sense of touch, or of feeling, is a very doubtful 

 matter, and one of which it is by no means easy to 

 give a general explanation which will meet all the 

 points, or even be very satisfactory upon any one of 

 them. This sense ought, strictly speaking, to include 

 not only those sensations which we fancy that we 

 derive from touching substances with our hands, such 

 as roughness and smoothness, hardness and softness, 

 heat and cold, and the like ; but it ought to include 

 all sensations which we can consider as being plea- 

 surable or painful, or in any way perceptible, except 

 those sensations which we refer to distinct organs, 

 and lose if those organs are destroyed or seriously 

 deranged. Among these last ought to be numbered 

 those influences of the atmosphere, which affect us 

 deeply in proportion to our sensibility, but which we 

 cannot refer to a sense of touch, as connected with 

 peculiar and localised organs, any more than we can 

 refer them to the other senses. The feeling of high 

 health and buoyant spirits, and also all the opposite 

 feelings down to absolute internal pain, of which we 

 are often unable to describe the seat, should also be 



included under this head, or else the sense of touch 

 ought to be subdivided into as many branches as 

 there are different sensations which impress us, not 

 through those local organs to which particular senses 

 are attributed. 



When we consider carefully the circumstances now 

 mentioned, and bear in mind how many different cir- 

 cumstances affect our bodily comfort, without having 

 any thing of a mental nature in them that we can 

 discover ; and further, when we bear in mind how 

 very often we are thus affected pleasurably or pain- 

 fully, when we can trace the affection to no source, 

 observed as physical, or suggested as intellectual, we 

 can hardly help admitting that we ought to give this 

 sense, one modification of which we call touch, as 

 extensive a locality as the whole sentient structures 

 of our body, and perhaps even those which we do not . 

 usually at least consider as being possessed of any 

 capability of sensation. The senses which have local 

 organs, the destruction of which puts an end to the 

 sense, do not participate with each other, unless per- 

 haps in that curious connexion which subsists between 

 smelling and tasting ; but this general sensation be- 

 longs to the organs of the allocated senses as well as 

 to the other parts of the body ; and often, as they are 

 more finely organised than structures of more rude 

 employment, they are the very first to be affected. 

 The converse holds equally good ; for this general 

 sense may be excited, and that to a degree highly 

 pleasurable or highly painful by the exercise of those 

 allocated senses upon particular objects. There are 

 sights and sounds, and odours, atid even savours, 

 which can make the whole frame thrill with delight ; 

 and there are others in each of the four classes which 

 can make it shudder with horror. All this may hap- 

 pen too without any suggestion of relation which 

 can give us the slightest ground for believing that the 

 matter is a mental one ; and thus we are constrained 

 to look upon it as a mere affection of the sentient body 

 by external circumstances. 



Such being the case, it follows by a most natural 

 analogy, that this general sense of the living structure 

 must be common to all the mammalia, only varying 

 in acuteness with the species, and indeed with the 

 individual ; it must do the latter of these as well as 

 the former ; for if we find this general sensibility, as 

 we may term it, so variable among the human race, 

 as the observation of every day proves it to be, we 

 cannot expect to find perfect uniformity among the 

 individuals of any species of mammalia whatever. 



When, therefore, we speak about the sense of 

 touch in these animals, we must be careful not to fall 

 into error, and suppose that it necessarily belongs to 

 some particular kind of surface, such as a naked 

 skin covered with small papillae ; for the sensation 

 can be conveyed as readily by a hair, a bristle, a por- 

 cupine's spike, or even the horn of an ox, as by the 

 most delicate finger belonging to the human race. 

 We know that the whiskers of nocturnal animals, and 

 probably the whiskers of all animals which have such 

 appendages, communicate a sense of the presence, 

 and even the approach of objects, with wonderful 

 quickness. The hair of horses, and indeed that of 

 all animals, respecting which the experiment is pro- 

 perly made, give proofs .that they are possessed of 

 equal sensibility to external objects. The sensibility 

 of leaping animals to friction, calculated to produce 

 voltaic action in their fur, is well known, from the 

 familiar experiment of rubbing a cat's back against 

 the grain ; and in order to show the perfect identity 



