EPIDERMIC PRODUCTS 259 



in question. Giving the idea of a semicircle and an ogive, 

 which we described above, he remarked to us that the idea 

 would perhaps be more easily fixed in the memory if we 

 associated with it the idea of the chronological order in 

 which the Roman and ogival art succeeded. Indeed, as 

 the Roman art preceded the ogival art, so the hoofs which 

 have the semicircular form precede those which have the 

 form of an ogive. 



This interpretation appeared to us ingenious ; this is why 

 we wished to give it here a place which seems to us to be 

 merited. 



Fig. 104. — Left Posterior Foot of a Horse : External Aspect. 



The wall of the hoof of a fore-limb, viewed on one of its 

 lateral surfaces (see Fig. 98), is more oblique than that of one 

 of the hind-hoofs looked at in the same way (Fig. 104), 

 This difference, very marked especially at the region of tlie 

 toe, is correlated with that of the direction of the pastern. 

 In fact, in the anterior limbs this is a little more obUque 

 than in the opposite ones. 



We have still to describe, in connection with the horse^ 

 some epidermic tissues, which are known as chestnuts. 



The chestnut is a small, horny plate which is found on. 



17 — 2 



