112 ORGANS OF SUPPORT, 



from abrasion. The inner toe of the anterior and posterior 

 extremities (A. d, B. ,) so imperfectly developed in most of 

 the digitigrade carnivora is generally longer in the plantigrade 

 and the aquatic species. 



In the true insectivorous quadrupeds without wings, as the 

 hedge-hogs shrews and moles, the jaws are more lengthened, 

 the canine teeth are often small, the molar teeth have broad 

 crowns with an outer and inner row. of sharp-pointed tuber- 

 cles to seize and bruise the insect food, the scapular arch 

 is strengthened by clavicles, the radius and ulna are separate 

 and moveable on each other, the rudimentary fibula is anchy- 

 losed to the tibia, all the feet are plantigrade and pentadacty- 

 lous and the toes and claws are strong for scraping and digging. 

 The orbit is continuous with the temporal fossa, the zygoma- 

 tic arch is very slender and straight, the infra-orbitary foramen 

 large, and the articulation of the lower jaw flat. There is 

 great mobility in the articulations of the hedge-hogs, as in 

 other spiny and scaly quadrupeds, to allow of their coiling 

 their body into the form of a ball for protection. The ante- 

 rior portion of the skeleton is more developed than the pos- 

 terior in the moles, to enable them more easily to burrow, 

 and in the cheiroptera to favour their flight through the air. 

 The cranial bones, the occipital, the parietal, and the frontal, 

 are remarkably extended forwards in the mole, compared with 

 the extent of the anterior bones of the face. The coronoid 

 process of the lower jaw rises high through the zygomatic arch, 

 and the angle of the jaw is prolonged backwards and a little 

 inwards over the mastoid portion of the temporal bone. 

 The fore part of the septum of the nose is ossified in this 

 animal as in the hogs, to support the nose in digging. 

 The spinous process of the axis is large and extended back- 

 wards, but the succeeding cervical vertebrae are like narrow 

 distant rings, almost destitute of spinous and transverse pro- 

 cesses, to allow the freest motion in this part with safety to 

 the enclosed spinal chord. The sternum is extended for- 

 wards to a great distance before the first pair of ribs, and is 

 carinated like that of a bird, to afford an extensive surface of 

 attachment to the large pectoral muscles ; and for the same 

 reason,, as well as to lodge large respiratory organs, the ribs 

 encompass a widely expanded thoracic cavity. The clavicles 

 are very short and strong, the scapulae long and narrow, the 



