466 THE CAT. [chap. xiii. 



(25) No digit of the pelvic limb has more than three phalanges.* 

 The first eight of the foregoing character?, together with the 12th, 

 17th, and 20tb, serve to distinguish the cat, as a mammal, from the 

 whole of the province Monocondyla. It is also distinguished from 

 all back-boned animals which are not mammals, in the follow- 

 ing points : 



(1) Tiie mandible consists only of one bone on each side, and 



directly articulates with the squamosal. 



(2) The malleus and incus are only small auditory ossicles. 



(3) The periotic bones anchylose together to form a petrous bone 



before anchylosing with parts of the occipital. 



(4) Tbere are two occipital condyles co-existing with a distinct 



basisphenoid. 



(5) There is a cribriform plate unless olfactory nerves are absent. 



(6) There is but one aortic arch, which arches over the left 



bronchus. 



(7) Two auricles and two ventricles co-exist with a membranous 



right auriculo-ventricular valve, and a single aortic arch. 



(8) There is more or less hair. 



(9) There is a corpus callosum and fifth ventricle. 



(10) The red-blood corpuscles are not nucleated. 



(11) There is a complete diaphragm, which acts as the main 



respiratory organ. 



(12) The male has a penis traversed by the urethra. 



(13) The female is provided with mammary glands. 



Such then is the cat's place in nature, so far considered. The 

 cat is a beast, or mammalian back-boned animal, because it has the 

 anatomical characters above enumerated, and the varying degrees 

 of its divergence from the other provinces and classes which go to 

 make up the sub-kingdom Vertebrata, are to be estimated according 

 to the variations of structural conditions which have been indicated in 

 the lists of characters above given. It remains to see the rank and 

 position which the cat may claim amongst its fellow mammals. 



§ 18. Besides the creature to the study of which this book is 

 devoted, all the animals most familiar to us and most generally 

 valuable to us — as our dogs and our domestic cattle — are members 

 of the class Mammalia. The name " beasts " is in more or less 

 general use to denote the various brute animals which belong to the 

 class ; but since man himself — the most individually numerous of 

 all the large animals — is, structurally considered, also a member of 

 it, the name " ISlammals " will be henceforth always exclusively 

 here employed to denote the creatures which compose it. 



Hitherto we have been occupied but with sub-lciugdoms, pro- 

 vinces, and classes ; the characters of subordinate groups of the 

 Invertebrate sub-kingdoms having no bearing upon the question as 

 to the cat's place in nature. Now, however, such subordinate 



* Tliis can only he afTirnicd of tlie i some aquatic mammals (Cetacea) has 

 pelvic limb, because the pectoral limb of | digits M'ith more than three phalanges. 



