(iK.MiKAI'IIH AL DISTKIIM TION 



143 





the exceptional facility which birds 

 have fur .-M.--IIIV )'.-IMI--I- impa--alil' by mammal-, 

 \\all.i< < lind- that the di.-t riliiit ion of manimaU 

 ( which allonl tlie Itest means of marking on" /oo- 

 geographical regions) correspond! with tliat of 

 hi nl- to an extent that one would not perhaps 

 ha\e previously anticipated. Hut with regard to 

 regions it must hi- reinemlered (1) that it 

 i- impii-siMc in most case* to draw any very 

 |j maiked boundary line between one region 

 mother ; (2) that the degree of divergence 

 between diHerent regions is different in different 

 eases ; and ( .'{ ) that, when any two regions are 

 i-.ni|>ai-cd, we have not the same degree of diverg- 

 ence between ditferent groups of the animal king- 

 dom, or between animals and plants belonging to 

 thf two regions. Obviously, the degree or corre- 

 vpondencc depends largely on the facilities for dis- 

 i. and largely also on the geological age of 

 ditlcieiit groups ; and both of these are varying 



factors. These consideration*! ln-ing premised, we 

 may now state briefly the limit* of tin- -i\ zoologi- 

 cal region* adopted by Wallace, as given in his 

 Ixl and Life. In the space to which the present 

 article is necessarily restricted it is im|K>Hsible to 

 give even the most fragmentary sketch of the 

 characteristic life of the dillerent regions, for which 

 the reader must be referred to the works cited at 

 the end of the article. 



( 1 ) Palmarctic Region, including Europe and north 

 temperate Axis and Africa to the northern border* of the 

 Sahara. 



(2) Ethiopian Region, consisting of all tropical and 

 South Africa, together with Madagascar and the Mas- 

 c.ii. in- Islands. 



(3) Oriental Region, comprising all Asia south of the 

 Pahi-arctic limits, and along with thin the Malay Islands 

 as far as the Philippines, Borneo, and Java. 



(4) Australian Region, as already defined and charac- 

 terised. Celebes might be referred almost with eoual 

 right to this or the previous region. New Zealand is 



1. Northern. 



2. Inner Asiatic. 

 8. Mediterranean. 

 4. Eastern Asiatic. 



The Terrestrial Floral Domains according to Oscar Drude : 



9. Tropical American. 



10. South African. 



11. Australian. 



12. New Zealand. 



6. Central North American. 

 0. Tropical Airican. 



7. East African Islands. 



8. Indian. 



13. Andine. 



14. Antarctic. 



1 



treated by Wallace as a highly peculiar sub-region of 

 this great region. 



(5) Nearctic Region, comprising all temperate and 



arctic North America, including Greenland, and extend- 



ii the south to an irregular line running from the 



1 ' rande del Norte on the east to a point nearly 



opposite Cape St Lucas on the west. 



Neotropical Region, the American continent south 

 of this line, together with the West Indian Islands. 



ll'-ilprin (see below) and others advocate the 

 iiiiinn of the Nearctic and Paloearctic regions under 

 the name of llolarctic, and introduce three transi- 

 tkraal tracts i the Mediterranean, embracing south- 

 l'.uio|>e, northern Africa, and western Asia 

 south of the Caspian and west of India, but exclu- 

 ~i\e oi' tin- southern half of Arabia; the Sonoran 

 embracing the north-west of Mexico; and 

 the A astro-Malaysian tract, embracing Celebes and 

 tin- smaller islands lying between it and New 

 (iiiinea ami Australia). Otherwise his major 

 faunal divisions of the globe are similar to those of 

 Wallace. 



On plant distribution the most important recent 

 works are those of Engler and Drude (c^ed at 



the end of the article ). Engler attempts to trace 

 the history of the vegetable kingdom since the 

 Tertiary period, and comes to the conclusion that 

 already in the Tertiary period four ' noral'elements ' 

 (Floremlemente) could \>e distinguished namely : 



(1) The Arcto-tertiary element, characterised by an 

 abundance of conifers and numerous genera of trees and 

 shrubs now prevalent in North America, or in extra- 

 tropical eastern Asia and in Europe. 



(2) The Paheotropical element, characterised by the 

 presence of the families and sub-families dominant in the 

 tropics of the Old World ; and still more by the absence 

 of certain families, groups, and genera found in the 

 territory of the Arcto-tertiary element. 



(3 ) The Neotropical or South American element, which, 

 according to Engler, must have had in Tertiary times 

 much the same character as that now possessed by tropi- 

 cal Brazil and the West Indies. 



(4) The old Oceanic element, consisting of forms which 

 possessed the power of traversing considerable stretches 

 of ocean and developing further on islands. 



The modern provinces of the vegetable kinjfdom 

 are sulxmUnated by Engler to these great divisions. 

 Drude, in the first place, distinguishes the oceanic 



