Man's place in nature, and other anthropological essays . ablishment of a relatively fixed base line, towhich the measurements, in all cases, must be referred,^or do I think it is a very difiicult matter to decidewhat that base line should be. The parts of the skull,like those of the rest of the animal framework, aredeveloped in succession: the base of the skull is formedbefore its sides and roof; it is converted into cartilageearlier and more completely than the sides and roof:and the cartilaginous base ossifies, and becomes solderedinto one piece long before the roof. I conceive then thatthe
Man's place in nature, and other anthropological essays . ablishment of a relatively fixed base line, towhich the measurements, in all cases, must be referred,^or do I think it is a very difiicult matter to decidewhat that base line should be. The parts of the skull,like those of the rest of the animal framework, aredeveloped in succession: the base of the skull is formedbefore its sides and roof; it is converted into cartilageearlier and more completely than the sides and roof:and the cartilaginous base ossifies, and becomes solderedinto one piece long before the roof. I conceive then thatthe base of the skull may be demonstrated development-ally to be its relatively fixed part, the roof and sidesbeing relatively movable. The same truth is exemplified by the study of themodifications which the skull undergoes in ascendingfrom the lower animals up to man. In such a mammal as a Beaver (Fig. 29), a line(a b) drawn through the bones, termed basioccipital,basisphenoid, and presphenoid, is very long in propor- 164 MANS i>LACE IN NATURE. BeavET. Fig. 29.—Longitudinal and vertical sections of the skulls ofa Beaver (Castor Canadensis), a Lemur (L. Catta), and aBaboon (Cynocephalus Papio), a &, the basicraniai axis; & c,the occipital plane; i T, the tentorial plane; a d, the olfactoryplane; f e, the basifacial axis; ch a, occipital angle; T i a, ten-torial angle; dab, olfactory angle; e f h, craniofacial angle;g h, extreme length of the cavity which lodges the cerebralhemispheres or cerebral length. The length of the basi-craniai axis as to this length, or, in other words, the propor-tional length of the line g h to that of a 6 taken as 100, inthe three skulls, is as follows:—Beaver, 70 to 100; Lemur, 119to 100; Baboon, 144 to 100. In an adult male Gorilla the cere-bral length is as 170 to the basicraniai axis taken as 100, in theNegro (Fig. 30) as 236 to 100. In the Constantinople skull(Fig. 30) it is as 266 to 100. The difference between the high-est Apes skull and
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Keywords: ., bookcentury1800, bookdecade1890, booksubj, booksubjecthumanbeings
