740 



CRANIUM. 



Nevertheless, this does not impair our ability 

 to deduce the internal capacity of the cranium 

 from an examination of its exterior ; since the 

 diplb'e between the two plates, in the spaces 

 intermediate to these ribs, seldom varies more 

 than one or two lines in its thickness. 



In a skull of ordinary capacity, the length, 

 measuring from the frontal spine to the longi- 

 tudinal sulcus, is five inches and a half; ks 

 width, between the bases of the petrous pro- 

 cesses of the temporal . bones, four inches and 

 a half; between the parietal fossae, five inches ; 

 and between the extremities of the alae mi- 

 nores, three inches and three quarters : its 

 depth, from the foramen magnum, four inches 

 and a half, from the ephippium three inches 

 and a quarter; and, from the front of the 

 olivary process, two inches and three quarters. 

 But observation proves to us that there is little 

 dependence to be placed on these measure- 

 ments ; scarcely any two skulls agree in their 

 diameters, for where one exceeds in a given 

 direction, it may fall short in some other. To 

 this conclusion we shall be led by the ex- 

 amination of skulls, not only of members of 

 the same community but even of persons con- 

 nected by the closest ties of consanguinity. 

 While, however, there is any doubt about the 

 matter, it is not to mixed communities we 

 should have recourse in our search for facts ; 

 but rather to the well-authenticated skulls of 

 such tribes as inhabit parts of the globe re- 

 mote from each other, and whose manners and 

 customs have, to the best of our belief, re- 

 mained stationary from time immemorial ; for 

 by this procedure we shall avoid the confusion 

 arising from a mixture of different races of 

 men whose respective dispositions have been 

 modified by intermarriage. 



The skulls of a North American Indian and 

 a Hindoo will be good examples to shew how 

 the diameters will vary. By making a longi- 

 tudinal section of each, we shall find, by ap- 

 plying a line between a spot about five-eighths 

 of an inch above the root of the nose, and 

 another about three-eighths of an inch above 

 the superior angle of the occipital bone, that 

 there is considerably more space above the line 

 in the Hindoo than there is in the American 

 Indian, while the distance to the foramen 

 magnum is much greater in the latter than in 

 the former. Again, if we make the usual ho- 

 rizontal section, it will be manifest that in 

 breadth the Indian will exceed the Hindoo 

 by nearly, and, sometimes, more than an inch, 

 although the latter has the advantage in length. 

 In the Negro, which, in length, is equal to 

 the Hindoo, the space above the line in a 

 vertical section is not absolutely, much less 

 relatively, so great towards the frontal bone 

 as in the shorter skull of the Indian; while 

 towards the posterior part of the parietal s it is 

 much greater, and in its breadth it falls but 

 little short of it. 



These three aboriginal types will suffice to 

 shew the endless varieties which must prevail 

 in mixed communities, and to satisfy us that 

 the forms of skulls are as numerous as the 



diversified modifications of character with 

 which the Creator has endowed the human race. 



Several naturalists have sought to establish 

 an analogy between the cranium and the ver- 

 tebrae, and have imagined that they had dis- 

 covered in the one a type of the other; in 

 other words, that the cranium is neither more 

 nor less than a gigantic vertebra which has been 

 submitted to some necessary modifications. 



In this sense the ephippium and basilar por- 

 tion of the occipital bone represent the body 

 of a vertebra; the foramen magnum, the ver- 

 tebral foramen ; the longitudinal spine of the 

 occipital bone, the spinous process; the ex- 

 panded portion of the bone as far as the mas- 

 toid portion of the temporals, the vertebral 

 plates ; the mastoid processes themselves, the 

 transverse processes ; the eminence above the 

 anterior condyloid foramina and the condyles 

 themselves, the superior and inferior oblique 

 processes ; and the notch behind the condyles 

 and the jugular notch, the notches which form 

 the conjugal foramina.* 



Others again regard the cranium as com- 

 posed of several vertebrae more or less com- 

 plete, which are so associated as to meet the 

 exigencies of the highly developed summit of 

 the medulla spinalis. The resemblance, how- 

 ever, of many of the parts to a vertebra is so 

 imperfect as to admit of the greatest license, 

 as respects both the fixing of the number and 

 the apportioning of the parts which severally 

 belong to them. The alteration of position, 

 too, to which they are necessarily subject to 

 enable them to accord with the change in direc- 

 tion which the nervous matter sustains, oasts 

 much confusion on the subject, and prevents 

 the mind from recognizing, at once, a similarity 

 which would be more apparent if they con- 

 tinued to be superimposed on each other as 

 they are in the spine instead of being arranged 

 at right angles with it.f 



The occipital bone certainly offers no dif- 

 ficulty to the detection of an analogy between 

 it and a vertebra; and we readily discern in it 

 a body ; a foramen ; two transverse, four arti- 

 cular, and one spinous process; and four 

 notches. These have already been pointed 

 out, and it is sufficient here to observe, that, 

 in this bone apart from the others, the basilar 

 process alone will represent the body, and the 

 lateral processes will be the type of the trans- 

 verse processes of the vertebra. 



By removing the bones of the face and 

 taking the sphenoid in conjunction with the 

 frontal bone, we shall (if we place the body 



* This was Dumeril's theory. See Consid. gen. 

 sur 1' Analogic entre tous les os et les muscles du 

 tronc des animaux. Magasiu Encyclopedique. 

 1808, t. iii. 



t The celebrated Goethe was among the first to 

 adopt this idea. He admitted the existence of 

 three vertebrae in the cranium, (Zur Naturwis- 

 senschat't iiberhaupt, &c. Stuttg. 1817-24.) The 

 further development of it occupied the attention 

 of O'Ken, Spix, Meckel, Geoffrey St. Hilaire, and 

 Can s. bee Meckel, Anat. Desc. &c. t. i. p. 631, 

 and Carus, Anat. Comp. par Jourdain, t. iii. 

 Introduction. ED. 





