6 ENTOMOLOGY FOR MEDICAL OFFICERS 



whether we take the fauna at present existing, or the fossil 

 remains of the geological epoch immediately preceding, we 

 find the same features positive and negative, namely, diverse 

 and abundant Edentata ; large Rodents ; no indigenous oxen, 

 sheep, or antelopes ; no Insectivora ; and no monkeys 

 resembling those that are found in the Old World. 



(4) The Arctogcean Province, including all the rest of the 

 world, namely. North America, Europe, Asia and most of its 

 large islands, Africa, and Madagascar. In this province there 

 are no Marsupials (except Opossums in North America), and 

 few Edentates ; but wild oxen, wild goats and sheep, 

 antelopes and Equidce are characteristic of most parts of it ; 

 and although some of its most striking mammals (such as 

 Elephants, Rhinoceroses, and Giraffes) are now found only in 

 its tropical parts, they, at an earlier geological period, were 

 widely distributed in its northern latitudes also. 



Considering the subject mainly from the other two points 

 of view, Huxley subdivided Arctogaea into four subprovinces, 

 as follows : — 



(a) America north of Mexico. Here Elephants, Rhinocer- 

 oses, and Equidse (except such as have run wild comparatively 

 recently) are absent from the existing fauna and are known 

 only in the fossil state. 



(b) Africa south of the Sahara. Here those elements of 

 the Arctogsean fauna, which in northern latitudes disappeared 

 during the glacial period, still survive, probably as immigrants 

 from the north. 



(c) " Hindustan." Here in the same way, probably, as in 

 Africa, most of the elements of the Arctogsean fauna survive, 

 but Giraffes are known only in the fossil state. 



(d) Europe, Northern Africa, and Asia north of tite tropic. 

 Here Elephants, Rhinoceroses, and Giraffes (Europe) are 

 known only in the fossil state. Elephants also in the subfossil 

 state (Siberia). 



Unfortunately Huxley's illuminating scheme is not so 

 commonly adopted as the more empirical schemes of Sclater 

 and Wallace, by which the world is partitioned entirely in 

 accordance with the distribution of existing species into the 

 following zoogeographical regions : — 



(i) Palcearctic Region^ 7raAa(o'y = old; a'/o/croj = the North), 



