912 



TEETH. 



and consists almost entirely of a blade divided 

 by a vertical fissure into two sub-equal com- 

 pressed pointed lobes : the points are less 

 produced than in the Felines, but the lower 

 sectorial of the hyaena is better distinguished 

 by the small posterior basal talon, from which 

 a ridge is continued along the inner side of the 

 base, and is slightly thickened at the fore-part 

 of the crown. According to the relative po- 

 sition of the crowns of the premolars the third 

 below ought to be the last, being analogous 

 to the fourth in the Mverridat, and the sec- 

 torial should be first true molar : we shall find 

 this view confirmed by the test of the mode of 

 succession of the permanent teeth. But the 

 mode of implantation of the premolar and 

 molar teeth may first be noticed. The first 

 upper premolar has but one fang; the second 

 and third have each two ; the sectorial tooth 

 has three, the two anterior ones on the same 

 tranverse line, the inner one supporting the 

 tubercle. The lower premolars and sectorial 

 have each two fangs, there being none truly 

 answering to the first above : the anterior 

 root of the lower (p. 1) sectorial tooth is 

 very strongly developed in the great extinct 

 Cave- Hyaena. 



33 

 The deciduous teeth consist of: i. 



I | Q _ O 



c. -l^r, m. o -5, = 28. The figure of the 

 1 1 o o 



skull of the young Hytsna crocuta in the 

 posthumous edition of the " Ossemens Fos- 

 siles," 8vo. 1836, pi. 190, fig. 3, shows that 

 stage when the correspondence with the 

 formula of the genus Felis is completed by the 

 appearance, in the upper jaw, of a small pre- 

 molar in the interspace between the canine 

 and first molar of the deciduous series : but 

 this appearance is due to the apex of the 

 first permanent premolar which cuts the gum 

 before any of the normal deciduous teeth are 

 shed : whether it is preceded, as in the dog, 

 by a deciduous germ-tooth in the foetus, I 

 know not. The first normal deciduous molar 

 is two-fanged, and has a more compressed 

 and consequently more carnivorous crown 

 than that of the second permanent premolar 

 by which it is succeeded. The second deci- 

 duous molar is the sectorial tooth : the inner 

 tubercle is continued from the base of the 

 middle lobe, and thus resembles the permanent 

 sectorial of the Glutton (Gulo) and many 

 other Mustelidce ; the deciduous tubercular 

 molar is relatively larger than in the adult 

 Hy<ena, and offers another feature of resem- 

 blance to the permanent dentition of the 

 Glutton. It is also worthy of remark that 

 the exterior incisor of the upper jaw is not 

 only absolutely, but relatively smaller in the 

 immature than in the adult dentition of the 

 hysena, and again illustrates the resemblance 

 to the more common type of dentition in the 

 Carnivora. 



The first and second deciduous molars be- 

 low have more compressed conical crowns 

 than their successors : the third deciduous 

 molar is the sectorial tooth, and, again, as 



in Gulo, has a better developed hinder tu- 

 bercle than the permanent sectorial ; it is not 

 displaced by this tooth, but, asjn other Car- 

 nivora, by a premolar of more simple cha- 

 racter. The permanent sectorial is deve- 

 loped posteriorly, and rises, like other true 

 molars, without displacing a deciduous pre- 

 decessor. 



The permanent dentition of the Hycena, as 

 of other genera or families of the Carnivora, 

 assumes those characteristics which adapt it 

 for the peculiar food and habits of the adult, 

 and mark the deviation from the common 

 type, which always accompanies the progress 

 to maturity. The most characteristic modifi- 

 cation of this dentition is the great size and 

 strength of the molars as compared with the 

 canines, and more especially the thick and 

 strong conical crowns of the second and third 

 premolars in both jaws, the base of the cone 

 being belted by a strong ridge which defends 

 the subjacent gum.* This form of tooth is 

 especially adapted for gnawing and breaking 

 bones, and the whole cranium has its shape 

 modified by the enormous development of the 

 muscles which work the jaws and teeth in 

 this operation.f Adapted to obtain its food 

 from the coarser parts of animals which are 

 left by the nobler beasts of prey, the hyaena 

 chiefly seeks the dead carcass, and bears the 

 same relation to the lion which the vulture 

 does to the eagle. In consequence of the 

 quantity of bones which enter into its food, 

 the excrements consist of solid balls of a 

 yellowish white colour, and of a compact 

 earthy fracture. Such specimens of the sub- 

 stance, known in the old Materia Medica by 

 the name of " album graecum," were dis- 

 covered by Dr. Buckland in the celebrated 

 ossiferous cavern at Kirkdale. They were 

 recognised at first sight by the keeper of a 

 menagerie, to whom they were shown, as 

 resembling both in form and appearance the 

 foeces of the spotted Hyaena; and, being 

 analysed by Dr. Wollaston, were found to be 

 composed of the ingredients that might be 

 expected in fo3cal matter derived from bones, 

 viz. phosphate of lime, carbonate of lime, 

 and a very small proportion of the triple 

 phosphate of ammonia and magnesia. This 

 discovery of the coprolites of the hyaena 

 formed, perhaps, the strongest of the links in 

 that chain of evidence by which Dr. Buckland 

 proved that the cave at Kirkdale, in York- 

 shire, had been, during a long succession of 

 years, inhabited as a den by hyaenas, and 

 that they dragged into its recesses the other 

 animal bodies, whose remains, splintered and 

 bearing marks of the teeth of the hyaena, 

 were found mixed indiscriminately with their 



* An eminent civil engineer, to whom I showed, 

 the jaw of a hyaena, observed that the strong conical 

 tooth, with its basal ridge, was a perfect model of a 

 hammer for breaking stones for roads. 



f " The strength of the hyaena's jaw is such that, 

 in attacking a dog, he begins by biting off his leg 

 at a single snap." Buckland, " Eeliquiae Diluvianae," 

 p. 23. 



