ENVIRONMENTAL SELECTION 31 



Herbivorous reptiles are not numerous, but of the Galapagos Islands, 

 where they do not suffer from mammalian competition, Darwin wrote: 

 "The species are not numerous, but the numbers of individuals of 

 each species are extraordinarily great . . . when we remember the 

 well-beaten paths made by the thousands of large tortoises — the many 

 t, ur tles — the great warrens of terrestrial Amblyrhynchus (=Conolo- 

 phus) — and the groups of the marine species basking on the coast-rocks 

 of every island — we must admit that there is no other quarter of the 

 world where this order replaces the herbivorous mammalia in so re- 

 markable a manner." 19 Similar examples could be increased indefi- 

 nitely. It must be remembered that a large number of individuals is a 

 correlative of a small number of species only when the conditions of 

 food supply are especially favorable. Thus the number of species of 

 butterflies in New Zealand is only about ten, with no especial abun- 

 dance of specimens. 



BIBLIOGRAPHY 



1) Chun, 1897, Die Beziehungen zwischen dem arktischen und antarktischen 

 Plankton, p. 36.-2) Vaughan, 1907, U. S. Nation. Mus. Bull., 59, p. 11-21.— 3) 

 Hartmeyer, 1909, in Bronn, Kl. & O., 3, Suppl., p. 1498 ff. — 4) Cleve, 1900, Ofv. 

 Svensk. Vet. Ak. Forh., 57, p. 139-144.— 5) Murray, 1895, CR. 3. Int. Zool. Cgr., 

 Leyden, p. 106.— 6) Ferroniere, 1901, Bull. Soc. Sc. Nat. Ouest France, (2) 1, p. 

 55_75._7) Gunther, 1880, Guide to the Study of Fishes, p. 209 & 259.-8) Fatio, 

 1890, Faune des Vertebres de la Suisse, 5, pt. 1, p. 46 ff.— 9) Sarasin, 1913. Z. Ges. 

 Erdkunde, p. 596.— 10) Pratt, 1935, Manual Invertebrates.— 11) Maxwell- 

 Lefroy, 1909, Indian Insect Life, p. 15.— 12) Henriksen & Lundbeck, 1917, 

 Greenland's Landarthropoder— 13) Handlirsch, 1910, Verh. zool.-bot. Ges. 

 Wien, 60, p. (160)-(185).— 14) Wallace, 1881, Island Life, p. 372.— 15) Mobius 

 & Heincke, 1883, Ostseefische, p. 185.— 16) Wallace, 1869, Malay Archip., 1, p. 

 123.— 17) Koningsberger, 1914, Java Zoologisch en Biologisch, p. 183.— 18) 

 Whitehead, 1893, Kina Balu, p. 51 ff.— 19) Darwin, 1884, J. Researches, etc. 

 (new ed.), p. 390. 



