Carpenter's principles of human physiology . umerous than those in front of the condyles, so thatthey are evidently intended to counteract this disposition; and we accord-ingly find ourselves able to keep up the head for the whole day with so slightand involuntary an effort that no fatigue is produced by it. Moreover, the c2 20 DISTINCTIVE CHARACTERISTICS OF MAN. plane of the foramen magnum and the surfaces of the condyles have a nearly-horizontal direction when the head is upright; and thus the weight of theskull is laid vertically upon the top of the vertebral column.—If these arrange-ments
Carpenter's principles of human physiology . umerous than those in front of the condyles, so thatthey are evidently intended to counteract this disposition; and we accord-ingly find ourselves able to keep up the head for the whole day with so slightand involuntary an effort that no fatigue is produced by it. Moreover, the c2 20 DISTINCTIVE CHARACTERISTICS OF MAN. plane of the foramen magnum and the surfaces of the condyles have a nearly-horizontal direction when the head is upright; and thus the weight of theskull is laid vertically upon the top of the vertebral column.—If these arrange-ments be compared with those which prevail in other Mammalia, it will befound that the foramen and condyles are placed in the latter much nearerthe back of the head, and that their plane is more oblique. Thus, whilst theforamen magnum is situated in Man just behind the centre of the base of theskull, it is found in the Chimpanzee and Orang Outan to occupy the middleof the posterior third (Fig. 3); and, as we descend through the scale of Fig.
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectphysiology, bookyear1
