LEPORID& 495 



with it. Thence it has spread, partly by man's agency, northwards 

 throughout temperate Western Europe, increasing rapidly wherever 

 it gains a footing ; and this extension is still going on, as is shown 

 by the case of Scotland, in which sixty years ago Babbits were little 

 known, while they are now found in all suitable localities up to the 

 extreme north. It has also gained admittance into Ireland, and 

 now abounds there as much as in England. Out of Europe the 

 same extension of range has been going on. In New Zealand and 

 Australia Eabbits, introduced either for profit or sport, have increased 

 to such an extent as to form one of the most serious pests that the 

 farmers have to contend against, as the climate and soil seem to 

 suit them perfectly, and their natural enemies are too few and 

 too lowly organised to keep their numbers within reasonable bounds. 

 In other cases Eabbits introduced into islands have become or 

 remained more or less distinct from their parent stock ; thus the 

 Eabbits both of the Falkland Islands and of Jamaica still show traces 

 of their descent from domesticated varieties, and have never reverted 

 to the ordinary brownish-gray type. And again, as was pointed 

 out by Mr. Darwin, 1 the Eabbits in the island of Porto Santo, near 

 Maderia, whose ancestors were introduced from Spain in 1418 or 

 1419, have formed quite a distinct diminutive race, barely half the 

 bulk or weight of English Eabbits, and differing in certain slight 

 details of colour and habits. 



Bibliography of Rodentia,. G. R. Waterhouse, " Observations of the Rodentia," 

 Mag. Nat. Hist. iii. (1839) ; Id. Ann. Nat. Hist. viii. and x. (1839-42) ; Id. 

 "On the Geographical Distribution of the Rodentia," Proc. Zool. Soc. 1839, pp. 

 162-174; Id. Natural History of the Mammalia, vol. ii. "Rodentia" (1848); 

 Gervais, Die. Univ. d'Hist. Nat. xi. p. 202 (1848); Brandt, " Untersuchungen 

 iiber die craniologischen Entwickelungsstufen und Classification der Nager der 

 Jetzwelt," Mem. de VAcad. Impir. de St. Petersbourg (1855) : Lilljeborg, 

 Systematisk CEfversight af de Gnagnde Daggdjuren, Upsala, 1866 ; Alston, "On 

 the Classification of the Order Glires," Proc. Zool. Soc. 1876, pp. 61-98 ; Trouessart, 

 " Catal. de Rongeurs, Vivants et Fossiles," Bullet. Soc. d'fitudes Scient. d' Angers, 

 1880-81 ; Coues and Allen, "Monographs of North American Rodentia," United 

 States Geol. Surv. of Territories, vol. xi. (1877); Winge, "Rodentia pa Lagos 

 Santa, Brazil," Mus. Lund. vol. iii. (1887) ; various papers by Peters in Monatsber. 

 Ak. Berlin, and by Alston, Anderson, Blanford, Dobson, Milne -Ed wards, 

 Thomas, and others, in Proc. Zool. Soc., Journ. Asiat. Soc. Beng., Ann. Mag. 

 Nat. Hist., etc. 



1 Variations of Animals and Plants, 2d ed. vol. i. p. 119. 



