Ill] OF PARTS OR ORGANS 189 



to equal the body-weight; and here again we find the same tendency 

 towards uniformity*. 



The converse to the unequal growth of organs is found in their 

 unequal loss of weight under starvation. Chossat found, in a 

 well-known experiment, that a starved pigeon had lost 93 per cent, 

 of its fat, about 70 per cent, of hver and spleen, 40 per cent, of its 

 muscles, and only 2 per cent, of brain and nervous tissues f. The 

 salmon spends many' weeks in the river before spawning, without 

 taking food. The muscles waste enormously, but the reproductive 

 bodies continue to grow. 



As the internal organs of the body grow at different rates, so that 

 their ratios one to another alter as time goes on, so is it with those 

 hnear dimensions whose inconstant ratios constitute the changing 

 form and proportions of the body. In one of Quetelet's tables 

 he shews the span of the outstretched arms from year to year, com- 

 pared with the vertical stature. It happens that height and span 

 are so nearly co-equal in man that direct comparison means little ; 

 but the ratio of span to height (Fig. 48) undergoes a significant and 

 remarkable change. The man grows faster in stretch of arms than 

 he does in height, and span which was less at birth than stature b}'' 

 about I per cent, exceeds it by about 4 per cent, at the age of 

 twenty. Quetelet's data are few for later years, but it is clear 

 enough that span goes on increasing in proportion to stature. How 

 far this is due to actual growth of the arms and how far to increasing 

 breadth of the chest is another story, and is not yet ascertained. 



* Cf. A. Brandt, Sur le rapport du poids du cerveau a celui du corps chez 

 diflFerents aniraaux, Bull, de la Soc. Imp. des naturalistes de Moscou, XL, p. 525, 

 1867; J. Baillanger, De I'etendu de la surface du cerveau, Ann. Med. Psychol. 

 XVII, p. 1, 1853; Th. van Bischoff, Das Hirngewicht des Menschen, Bonn, 1880 

 (170 pp.), cf. Biol. Centralhl. i, pp. 531-541, 1881; E. Dubois, On the relation 

 between the quantity of brain and the size of the body, Proc. K. Akad. Wetensch., 

 Amsterdam, xvi, 1913. Also, Th. Ziehen,^ Maszverhaltnisse des Gehirns, in 

 Bardeleben's Handh. d. Anatomie des Menschen; P. Warneke, Gehirn u. Korper- 

 gewichtsbestimmungen bei Saugern, Journ. f. Psychol, u. Neurol, xiii, pp. 355-403, 

 1909; B. Klatt, Studien zum Domestikationsproblem, Bibliotheca genetica, ii, 

 1921; etc. The case of the heart is somewhat analogous ; see Parrot, Zooi. Ja^r&. 

 (System.), vii, 1894; Piatt, in Biol. Centralhl. xxxix, p. 406, 1919. 



t C. Chossat, Recherches sur I'inanition, Mem. Acad, des Sci., Paris, 1843, 

 p. 438. 



