506 HEIGHT AND WEIGHT IN RELATION TO BUILD 



rapid growth in length of thigh and forearm, but he found acceleration in growth 

 of bone-girths accompanying growth in length of the long bones of the limbs, 

 acceleration in muscle-girths following this period. 



Having thus reviewed some of the fundamental features of relative linear 

 proportions we shall take up briefly a more detailed consideration of certain of the 

 more important of these measurements. 



VERTICAL MEASUREMENTS. 



(Chart I, p. 534; Tnlde K, p. 550.) 



These measurements are taken from the horizontal level of one point to that 

 of another, not directly between the points named. 



Vertex to external acoustic meatus. The curve of the external meatus follows, 

 with a few slight modifications, the data of Quetelet (see table E). For the taller 

 individuals I have had the data of Mr. Puestow, referred to in connection with the dis- 

 cussion of head-volume, page 493. The data of Hrdlicka (1899) and of Godin (1910) 

 correspond closely with those of Quetelet. The Swiss children reported by Ernst 

 (1906) and Schwerz (1910) give smaller values by about 0.5 per cent of the stature. 

 Girls give slightly smaller values than boys of the same stature. It is the relatively 

 slow growth of the part of head above the external acoustic meatus that chiefly 

 accounts for the decrease in the relative height of the head from infancy to maturity. 

 Correlated with this relatively slow growth of the cranial portion of the skull we 

 find, according to the data of Mies (1894), that the relative weight of the brain 

 decreases from about 17 per cent of the weight of the body in the infant to 2.86 

 per cent at 18 to 19 years of age. In adults of average build it appears to be in the 

 neighborhood of 2.5 per cent. 



Vertex to top of larynx. I have chosen the level of the top of the larynx to mark 

 the boundary between the head and the trunk because of its convenience for use in 

 the study of head-volume and because the structures above this level, including 

 the upper cervical region, all belong essentially to the head. In relation to the 

 vertebrae, however, this level shifts downward during development. According to 

 Symington (1887), in the infant at 1 year the upper border of the thyroid cartilage 

 lies opposite the junction of third and fourth cervical vertebra?; in a 6-year-old 

 child, opposite the body of the fourth cervical vertebra; in the adult, opposite the 

 upper margin of the body of the fifth cervical vertebra. In the living it lies some- 

 what more distal than in the cadaver position above described, and in the aged may 

 sink considerably lower. The curve given is based on measurements I have made 

 in a series of children and young adults. It runs fairly close to a curve based on 

 Quetelet's data on vertex to the "fin du menton." (See table E.) Zeising (1858) 

 apparently selected a lower point on the larynx than that selected by me. The data 

 of Godin (1910) correspond more nearly with Quetelet's vertex, naissance du menton 

 than with his vertex, fin du menton data, and give lower values by about 1 per cent 

 of the stature. Landsberger (1888) gives data which closely correspond with those 

 here plotted for children. He measured from chin to vertex. 



While there are well-marked individual variations, the relative height of the 

 head usually varies with stature and is less in tall than in short individuals. Accord- 



