52 ON THE PLACE OF MAN IN THE SCALE OF BEING. 



commonly seen to be in an inverse proportion 1o that of the cranium. To 

 this column, the ribs and extremities are merely appendages, which we find 

 more or less developed in the various tribes, and often entirely absent ; whilst 

 the vertebral column is never wanting, although reduced in some species to a 

 very rudimentary state. It is interesting to compare its various conditions, 

 with those which have been noticed in the external skeleton of the Articulata. 

 In the lowest animals of the group, locomotion is principally or even entirely 

 performed by flexion of the body itself; and here, as in the worm tribe, we 

 find the skeleton extremely flexible, the whole being comparatively soft, and 

 its divisions indistinct. This is the case, for example, in the Lamprey and 

 other Cyclostome fishes : in which there is no distinct division into vertebrae, 

 the spinal column scarcely possessing even the density of cartilage. In pro- 

 portion, however, as distinct members are developed, and the power of loco- 

 motion is committed to them, we find the firmness of the spinal column in- 

 creasing, and its flexibility diminishing ; and in Birds, in which, as in In- 

 sects, the movements of the body through the air are effected by muscles that 

 must have very firm points of support, the vertebral column is much conso- 

 lidated by the union of its different parts, so as to form a solid frame-work. 

 As a general rule, then, the mobility of the extremities, and the firmness of 

 the vertebral column, vary in a like proportion. The number of these ex- 

 tremities in Vertebrata never exceedsybz'/ and two of them are not un fre- 

 quently absent. The power of locomotion is not developed to nearly the 

 same proportional extent, as in the Articulata ; the swiftest bird, for example, 

 not passing through nearly so many times its own length in the same period, 

 as a large proportion of the Insect tribes : but it is far greater than that, which 

 is characteristic of the Mollusca ; and there is no species that is fixed to one 

 spot, without the power of changing its place. On the other hand, the high- 

 est Mollusca approach them very nearly in the development of organs of spe- 

 cial sense, of which Vertebrata almost invariably possess all four kinds sight, 

 hearing, smell, and taste. 



23. The perfection of the Articulate structure has been shown to consist 

 in the development of those powers which enable the animal to perform 

 actions denoting the highest instinctive faculties. That of the Vertebrata 

 evidently tends to remove the animal from the dominion of undiscerning, 

 uncontrollable, instinct; and to place all its operations under the dominion of 

 an intelligent will. We no longer witness in these operations that uniformity, 

 which has been mentioned as so remarkable a characteristic of instinctive 

 actions. There is evidently, among the higher Vertebrata especially, a power 

 of choice and of determination, guided by a perception of the nature of the 

 object to be attained, and of the means to be employed, constituting the 

 simplest form of the reasoning faculty ; and the amount of this bears so close 

 a relation with the development of the cerebrum, that it is scarcely possible to 

 regard the two as unconnected. In Man, whose cerebrum is far larger in pro- 

 portion to his size, as well as more complex in its structure, than that of any other 

 animal, the reasoning faculties attain the highest perfection that we know to 

 be anywhere manifested by them in connection with a material instrument ; 

 the instinctive propensities are placed under their subjection; and all his acts, 

 excepting those immediately required for the maintenance of his organic func- 

 tions, are put under their control. It is to Man, therefore, that what was just 

 now stated, of the predominance of the nervous system in Vertebrata, parti- 

 cularly applies ; but the same may be noticed, though in a less striking degree, 

 throughout the group. Not only is the influence of the nervous system to be 

 traced, in the sensible movements which they perform ; but also in various 

 modifications of the organic functions, which take place under the influence 

 of particular states of mind, and the occurrence of which there is no reason 



