237 



horse of the same height (92 cm.) and akiill length (41 cm.); it 

 was 128 kg. By comparison with Cornkvin's heavy Belgian horse 

 I now find and exponent of relation of 0.2528. The heaviest of 15 

 male horses, according to Colin'), a Percheron of 501 kg. dead 

 weight, compared with the lightest male horse ("de petite taille") of 

 this gronp, of 288 kg. dead weight, gives an exponent of relation 

 of 0.1855. The heaviest horse was probably less emaciated than 

 the lightest; hence the exceedingly low exponent. 



For two groups, each of six domestic rabbits, formed from 

 Müller's records'), one of an average body weight of 4386 gr., 

 the other of 1727 gr., I find an exponent of relation of 0.2512. 

 Two groups, each of five male moles, from Manouvhieh »), yield 0.234. 



Eight domestic ducks, of 1756 gr. average body weight, compared 

 with a dwarf of the same domestic species, of 755 gr. body weight, 

 according to Timmann's') records, yield an exponent of relation of 

 0.3096. A cock of 1745,7 gr. body weight with a hen of 985. 2 gr., 

 from Falck's ') report, yield an exponent of relation of 0.2248. 



Two groups, each of six Bull Frogs (Rana catesbyana), according 

 to Donaldson "), of 244.5 and 164 gr. mean body weight, give an 

 exponent of relation of 0,2516. Also the average cranial capacities 

 of 9 male and Jl female Australian aboriginals in relation to the 

 mean volumes of the six long bones, from Hauler's observations^), 

 yield an exponent of 0.2770. 



In the Figures 2 and 3 the dotted lines give a graphical record 

 of the relations of the weights of the brain and the body between 



') G. Colin, Traite de physiologie comparée des animaux. S^e Edition, Tome I, 

 p. 302. Paris 1886. 



*) E. Muller, Vergleichende Untersucbungen an Haus- iind Wildkaninchen. 

 Zoologische Jahrbücher. (Spengel). Abteilung fur Allgem. Zoölogie and Physiologie 

 der Tiere. Band 36, p. 585. Gesamttabelle XXVa. Jena 1919. 



'). L. Manouvrier in Dictionnaire de Physiologie par Gh. Richet, article 

 .Gerveau", p. 680. Paris 1898. 



*) 0. TiMMANN, Vergleichende Untersuchungcn an Haus- uud Wildenten. Zoolo- 

 gische Jahrbücher, ibid., p. 653. 



^) G. Ph. Falck, Beitrage zur Kenntnis der Bildungs- und Wachsthnmsgeschichte 

 der Thierkörper. Schriften der Gesellscliaft zur Beförderung der gesammten Natur- 

 wissenschaften zu Marburg. Band 8, p. 242. Marburg 1857. 



6) H. H. Donaldson, On a Formula for Determining the Weiglit of the Central 

 Nervous System of the Frog from the Weight and Length of its Entire Body. 

 University of Ghicago Decennial Publications. Vol. 10. (1902), p. 7. 



7) Otto Hauger, Der Gehimreichtum der Australiër und anderer Horainiden, 

 beurteilt nach ihrem Skelet. Anatomische Hefte (Merkel und Bonnet;. I. Abteilung. 

 Heft 179. Band 59, p. 589: Tabelle I, p. 616-617: Tabelle UI. München und 

 Wiesbaden 1921. 



