1337 



It can be derived from numerous determinations of the size of 

 the eye of higher and lower vertebrates by Lapicque and Laugirr ') 

 that the exponent of relation for the area of the retina must in 

 general lie at 0.28. 



Hence we are induced to look for the cause of the existing 

 enlargement of the nerve cell centre in the enlargement of the 

 receptive area of the organ of sight. 



I purpose to treat this relation and the signiticance of the eye- 

 area, which in my opinion, is to be found in the ratio of the 

 motive force and the moved mass for large and for small animals, 

 in a subsequent communication. 



1) L. Lapicque, La grandeur relative de I'oeil et l'appréciation du poids encé- 

 phalique. Comptes rendus de l'Académie des Sciences. Paris 1908. (2). Tome 147, 

 p. 209 — 212. — Relation du poids encéphalique a la surface rétinienne dans 

 quelques ordres de Mammifères. Ibid. 1910. (2). Tome 151, p. lo93^i396. Also: 

 L. Lapicque et H. Laugier, Relation entre la grandeur des yeux et le poids de 

 Tencephale chez les Vertébrés inférieurs. Comptes rendus de la Société de Biologic. 

 Paris 1908. Tome 64, p. 1108-1110; G. Waterlot, Determinations de poids 

 encéphaliques et de grandeurs oculaires chez quelques Vertébrés du Dahomey. 

 L. Lapicque, Remarques sur la série depesées encéphaliques recueillies au Dahomey 

 par M. Waterlot. Bulletin du Muséum d'Histoire naturelle. Paris 1912, p 491 — 497. 



According to the first determinations the exponent was found somewhat lower; 

 in the above meant sense it became 0.25. 



