INCREASE IX THE WEIGHT OF THE ENTIRE BODY. 49 



see why this measure should be best, if we consider for 

 a moment the significance of linear measurements 

 which are sometimes taken in place of it. Our 

 bodies are developed in three dimensions, and give an 

 irregular geometrical form which, moreover, changes 

 with age. In consequence of this, the variation in any 

 linear measure, as stature, for instance, serves only as a 

 rough index of the changes which have taken place 

 in the other two diameters. The accompanying figure, 

 taken from Langer, 1 shows at a glance that a man is not 

 a big child, for when the child is enlarged to the size of 

 a man, as in this illustration, its short legs, large trunk, 

 and enormous head are in sharp contrast with the same 

 parts in the adult. 



This change in geometrical form is well exemplified 

 by a citation from Thoma. 2 Starting with the figures 

 of Quetelet, he makes the following tabulation : 



Male new-born, stature 500 mm., body- weight 3*1 k ; los. 

 Man at 30 years 1686 ,, 66'i 



If we take now the specific gravity of the entire body 

 of the new-born as '90,3 and that of the man at thirty 

 years as '93, we get as corresponding volumes 



Male, new-born 3'44 lit. 



Man, 30 years 71*08 ,, 



By referring back to the first table we see that during 

 the first thirty years of life stature has increased 



1 Langer, Anatomic d. iiussercn Formen d. mensch. Korpers, 1884. 



2 Thoma, Grosse und Geivicht der anatomischcn Bestandtheile 

 des mcnschlichcn. Korpers, 1882. 



3 As the specific gravity of almost all the solid and fluid con- 

 stituents of the body is more than i, it is at first sight curious that 

 the entire body should have a specific gravity below I. These 

 observations were, however, made on intact bodies, the air and 

 gases remaining in the cavities. Hence the lower figures which 

 were obtained. As the relative specific gravity is here the point 

 of interest, the peculiarity of the absolute figures need not be 

 further discussed. 



4 



