418 ETHNICAL FORMS AND UNDESIGNED ARTIFICIAL 



further restrained in a fixed position than necessarily results from 

 the recumbent posture in which the body is retained by the bandages 

 securing it in the cradle. This fact I have satisfied myself of from 

 repeated observation. But the consequence necessarily is, that the 

 soft and pliant bones of the infant's head are subjected to a slight 

 but constant pressure on the occiput during the whole protracted 

 period of nursing, when they are peculiarly sensitive to external 

 influences. Experiments have shewn that at that period the bonea 

 specially affected by the action of the cradle-board are not only 

 susceptible of changes, but liable to morbid affections, dependent on 

 the nature of the infant's food. Lehmann supposes the craniotabes 

 of Elsasser to be a form of rachitis which affects the occipital and 

 parietal bones during the period of suckling ; and Schlossberger 

 ascertained by a series of analyses of such bones that the 63 per 

 cent, of mineral constituents found in the normal occipital bones of 

 healthy children during the first year, diminished to 51 per cent, in 

 the attenuated parts, and in some cases even to 28 per cent, in the 

 thickened and spongy bone.* The fluctuations in proportion of the 

 mineral constituents of bones are considerable, and vary in the 

 different bones, but in the osseous tissue they may be stated at from 

 67 to 70 per cent. It is obvious, therefore, that, under the peculiar 

 physiological condition of the cranial bones during the period of nursing^ 

 such constant mechanical action as the occipital region of the Indian 

 pappoose is subjected to, must be productive of permanent change. 

 The child is not removed from the cradle-board when suckling, and is 

 not therefore liable to any counteracting lateral pressure against its 

 mother's breast. One effect of such continuous pressure must be to 

 bring the edges of the bones together, and thereby to retard, or arrest 

 the growth of the bone in certain directions. Of this I have observed 

 distinct proof in an extreme case of artificial deformation in a Flat- 

 head skull, from the occurrence of exostosis at the sutures. The 

 same cause must tend to shorten the zygoma ; whereas if it were 

 possible to alter the adult skull by pressure similarly applied, the 

 zygomatic arch being then fully developed, would betray its effects 

 by bulging out, and increasing the width of the face. One element 

 of variation in the parieto-occipital flattening resulting from the or- 

 dinary use of the cradle-board, depends on the greater or less eleva- 

 tion of the pillow. In many Indian skulls, where there is no in- 



* Schlossberger, Arch. f. phys. Heilk. Lehmann, Physiol, Chem. Vol. III. p. 28. 



