80 



BONES OF THE HEAD. 



been given to this subject, on the Continent by Caras, V. Baer, R. Wag'nerv, 

 Virchow, Welcher, Huschke, Lucob and others, and in this country by Busk, 

 Huxley, Cleland. and Barnard Davies. From the researches of these authors the 

 general conclusion may be drawn, that external measurements alone are insuffi- 

 cient to supjjly all the information required as to the form and relations of the 

 parts of the skull, and that it is necessary to combine with tliem numerous 

 measurements which can only be made in the skull opened by a mesial vertical 

 section. The observations of Vii-chow, Huxley, and Cleland have also shown the 



Fig. 07. 



Fi-. 68. 



Fig. 67. — Skull op European texdtn-g tcvards the Brachycephalic Fokji 



(Carpenter). ^ 



Fig. 68. — Strongly DoLicnocEPiiALic Skull of European (Carpenter). ^ 



importance which is to be attached to the relations of the basi-cranial axis as a 

 very uniform standard of reference for comparing the direction and dimensions of 

 other jjarts. Without going into farther detail here, it may be mentioned that 

 the angle formed by the basicranial axis with the line of the cribrethmoid plate, 

 the '• ethmo-cranial "' angle of Huxley, and nearly the '• saddle-angle " of Yirchow, 

 is about 140° in British and Western European skulls, diminishing in the highest 

 forms, and opening out in the lower, till in quadrupeds the two lines run almost 

 into one ; and that the " loremaxillary "' angle of Huxley, between the anterior 

 extremity of the basicranial axis and the front of the incisor ridge of the upper 

 jaw, gives a reliable estimate of the degree of facial projection ; varying in diffe- 

 rent skulls from 83° to 110°, so that the angle above 95° is indicative of progna- 

 thism, below it of orthognathism. (On the foregoing subject consult, in addition 

 to the work? of Camper, Cuvier, Blumenbach, La^\Tence, Carpenter, and other 

 authors quoted, the following : viz., Transl. of the Memoir of Retzius in the Brit, 

 and For. Med. Chir. Review, 1860 ; Owen, in Trans. Zool. Soc. vol. iv.. 18.ol ; 

 Busk's papers in Trans. Ethnol. Soc. Lond., vol. i., 1861, and Joum. of Anthrop. 

 Inst., vol. iii. ; Huxley's Lect. '• Man's Place in Natiu-e," and in Jomn. of Anat. 

 and Physiol., vols. i. and ii. ; Thurnam and Davies, " Crania Britannica," and 

 Davies. " Tliesaurus Craniorum," 1807 ; Cleland's Memoir- in Philos. Ti-ans.. 18G9 ; 

 as also Vu-chow, in his work on the" Development of the Cranial Basis," 18.57, and 

 in Germ. Quart. Mag., Nov. 1871 ; Huschke, Schadel. Him, and Seele, &c., 1854; 

 and Lucae, Zur Morphol. der Rassen schadel, 1861-04.) 



IV. Irregularities of Form. — The most fi'equent iiTegulaiity in the fonn of the 

 ,<;kull is want of symmetry. This sometimes occm-s in a marked degi'ee, and there 

 is probably no skull perfectly symmetrical. The condition which has been ob- 

 served to co-exisb most frequently with iiTegular fonns of skull is xi/noxfosh. or 

 premature obliteration of certain of the sutm-es. The cranial bones 'increase in 

 size principally at their margins ; and when a suture is prematurely obliterated 

 the growth of the skidl in the dnection at right angles to the line of sutiu-e may 

 be supposed to be checked, and mcreased growth in other directions may take 

 place to supply the defect : but this condition is not constant (see Huxley, 

 loo. eit. ; ■Virchow, " Gresammelte Abhandlungen/' 1856 ; J. Barnard Davies, 



