THEIR FOOD. 281 



the animal is supplied with concentrated cereal food and 

 hay, with an admixture of nutritious roots and mashes, or 

 green fodder. The consequence is, that the crowns of the 

 active molars do not get worn down with sufficient rapidity 

 to make way for the tooth forming behind, and abnormal or 

 morbid results follow : — 



1st. The used surface of the crown, instead of being un- 

 equal and terraced, is worn smooth and flat, in some in- 

 stances even like a slab of polished marble. 



2nd. The uncalcified back portion of the capsule of the 

 tooth in action, instead of remaining distinct, becomes, from 

 the undue pressure behind, united with the formative capsule 

 of the contiguoiis back tooth, the development of which is 

 not retarded, and the two separate molars are fused into one 

 unwieldy mass, covered by a continuous shell of cement. A 

 fine example of this state is presented by an adolescent cra- 

 nium in the Museum of the College of Surgeons (No. 2665, 

 Osteol. Cat.), in which two molars and apparently part of 

 the third in front are united into one ; and the pressure has, 

 besides, acted so as to contract the palate, and bring the 

 opposite molars nearly into contact in front. 



3rd. The anterior fangs of the tooth in action are gradu- 

 ally absorbed while the corresponding portion of the crown 

 remains unworn and is projected forwards, like a foreign 

 body, beyond the edge of the alveolus. I observed a very 

 remarkable instance of this morbid condition in the cranium 

 of a ' Mukna ' Elephant, preserved in the Natural History 

 Museum at Florence. On the right side, in this specimen, 

 there are three molars in situ : the last in germ, the penulti- 

 mate partly worn, and agglutinated to it in front the ex- 

 truded body, without fangs, of the antepenultimate, which is 

 projected forwards and upwards across the diastemal inter- 

 val, so as actually to press against the palatine floor of the 

 maxillary bones. In this case the morbid pressure had caused 

 the absorption of the plate of bone forming the base of the 

 sheath of the incisor, which is indicated by a deep pit, and it 

 probably led to the death of the animal, with great torture. 



4th. The capsule of the last molar being constrained for 

 room, by the undue resistance in front of it, there is not suffi- 

 cient space for the normal arrangement of all the plates as 

 they are successively calcified, and the hhidermost become 

 distorted in position. A fine example of this malformation 

 is presented by the last lower molar, fig. 90, of the ' British 

 Fossil Mammalia.' ' The tooth is there described as being- 



1 Op. cit. pp. 226 and 233, and Cat. 

 Foss. Mam. &c. Coll. of Sur. No. 567, 



make the rectification here indicated, 

 since the figure has been copied by an 



p. 134. It is the moro necessary to eminent French Palaeontologist, on the 



