HIGH SCHOOL ZOOLOGY. 



147 



Fig. 102.— Skeleton of Cat. (After Strauss-Dmkheim.) 

 oe, occipital riflse ; sc, scajwla ; il, ilium ; is, ischimn ; f , femur ; pa, patella ; t, tihia ; 

 fi, fibula ; c, calcaneum ; int, metatarsus ; me, metacarpus ; a, pisifonn ; r, nwlius ; 

 u, ulna; h, humerus; x, xiphoid cartilage; m, manubrium sterni; el. clavicle; 

 or, cricoid ; th, thyroid. 



the sternum presents more traces of its original mode of 

 formation than it does even in Reptiles. Thus, in the Cat, it is 

 composed of eight pieces, the first of which, the manubrium, 

 'carries the clavicles in the mammals in which these bones are 

 complete, while the last, the xiphoid cartilage, does not become 

 ossified like the other pieces. 



6. The skull of the cat is, of course, modified in connection 

 with the strong teeth and muscular development of the jaws, 

 but apart from such superficial characters, a knowledge of its 

 structure will enable the student to understand that of the 

 other mammals, and to compare it with that of the lower forms. 

 It is first to be observed that the bones of the ci-anium and face, 

 with the exception of the mandible, are immovably united to- 

 gether, as in the turtle or bird, but the sutures remain quite 

 distinct, and the bones can be readily separated from each other in 

 a macerated skull. The first thing that strikes one in compaiing 



