THE APPARATUS OF TASTE. 813 



digits, but by the whcle plantar surface. Therefore it is, that we find on this face a kind 

 of epidermic pad covering five fibro-adipose tubercles : four small ones placed along the 

 four principal digits the fifth or thumb not being sufficiently developed to reach the 

 ground and a large central one, circumscribed in front by the others. This ar- 

 rangement is destined to diffuse the pressure caused by the weight of the body (and, 

 doubtless, to ameliorate the concussion arising from the exertions these animals make, as 

 well as to insure their footsteps' being noiseless in approaching their prey). In the Dog, 

 the claws may be used for burrowing in the ground. 



In the Cat, the claws are very sharp and retractile ; being capable of erection and 

 depression in the interdigital spaces, by means of a small yellow elastic ligament 

 passing from the second to the third phalanx. This animal's claws constitute its most 

 powerful weapon of attack and defence. 



4. The Frontal Horns. 



These are conical horny sheaths, more or less large, crooked, and annulated 

 transversely, formed by concentric layers of epithelial cells and some pigment corpuscles. 

 The horns' grow like the epidermis and the hair, their elements being secreted by that 

 portion of the corium spread over the osseous cores of the frontal bones, and which 

 completely envelope these ; this portion of the skin is remarkable for its great 

 vascular ity. 



(The length, direction, and general form of the horns varies in "Ruminants, not only 

 with regard to species, age, and race, but also the sex. The Bull, in the Bovine species, 

 generally has short, thick, powerful horns; the Cow long and slender ones; and the Ox 

 large, long, and strong ones. Some breeds have no horns at all ; the same with the 

 Goat species, though generally the horns in these are long, flattened, and curved 

 backwards and downwards. With the Earn, the horns are sometimes immense and very 

 powerful, being of a spiral form. They are usually less, or nltogether deficient, in the 

 Ewe. In the Bovine species, the transverse rings on the horns serve to indicate the age t 

 the first appearing after two years.) 



5. The Chesnuts. 



This name^ is given to a little horny (oval or round) plate found, in the 

 Horse, on the inner face of the fore-arm in the lower third of the region, 

 and at the upper extremity of the inner face of the metatarsal bone. It is 

 composed of a mass of epithelial cells, arranged in tubes like the horn of 

 the hoof. In Solipeds, the chesnut is the representative of the thumb. 

 That on the posterior limbs is absent in the Ass; in the Mule it is very 

 small. 



(In fine-bred Horses, this horny production is much less developed 

 than in the coarser breeds. It is always smaller in the hind limbs. 



In the hind and fore-legs, we also find a similar, but smaller corneous 

 mass, growing from the skin of the fetlock, and named the ergot. Like the 

 chesnut, it bears the same relative development in fine and coarse-bred 

 horses.) 



CHAPTER II. 



APPARATUS OF TASTE. 



THE sense of taste permits the appreciation of savours, or the sapid properties 

 of bodies. 



Two nerves the chorda tympani and the lingual branch of the ninth pair 

 appear at present to be the only sensory filaments endowed with the 

 exercise of this function. They ramify in the lingual mucous membrane 

 which is thus made the organ of taste. 



