CiiAi'. I. LOCxVLIZED STRUCTURES. 41 



SECTION XI. 



COMMUNITY OF STKUCTURE AMONG ANIMALS LIVING IN THE SAME REGIONS. 



The most interesting result of the earliest investigations of the fauna of Australia 

 was the discovery of a type of animals, the Marsupialia, prevailing upon this conti- 

 nental island, which are unknown in almost every other part of the world. Every 

 student of Natural History knows now that there are no Quadnanana in New Holland, 

 neither Monkeys, nor Makis: no Inscctivora, neither Shrews, nor Moles, nor Hedgehogs; 

 no true Carnivora} neither Bears, nor Weasels, nor Foxes, nor Viverras, nor Hyenas, 

 nor Wild Cats; no Edentata, neither Sloths, nor Tatous, nor Ant-eaters, nor Pangolins; 

 no Pach)/dcrms, neither Elephants, nor Hippopotamuses, nor Hogs, nor Ehinoceroses, 

 nor Tapirs, nor Wild Horses ; no Rimiinantia, neither Camels, nor Llamas, nor Deers, 

 nor Goats, nor Sheep, nor Bulls, etc., and yet the Mammalia of Australia are 

 almost as diversified as those of any other continent. In the words of Waterhouse,^ 

 who has studied them with particular care, "the Marsupialia present a remarkable 

 diversity of structure, containing herbivorous, carnivorou.s, and insectiverous species ; 

 indeed, we find amongst the marsupial animals analogous rejiresentations of most of 

 the other orders of Mammalia. The Qnadnimana are represented by the Phelangers, 

 the Carnivora by the Dasyuri, the Insectivora by the small Phascogales, the Rwninantia 

 by the Kangaroos, and the Edentata by the Monotremes. The Cheiroptera are not 

 represented by any known marsupial animals, and the Rodents are represented by a 

 single species only ; the hiatus is filled up, however, in both cases, by placental 

 species, for Bats and Rodents are tolerably numerous in Australia, and, if we except 

 the Dog, which it is probable has been introduced by man, these are the only pla- 

 cental Mammalia found in that continent." Nevertheless, all these animals have in 

 common some most striking anatomical characters, which distinguish them from all 

 otlier Mammalia, and stamp them as one of the most natural groups of that class ; 

 their mode of reproduction, and the connection of the young with the mother, are 

 difl'erent ; so, also, is the structure of their brain, etc." 



Now, the suggestion that such peculiarities could be produced by physical agents 

 is for ever set aside ])y the fact that neither the birds nor the reptiles, nor. indeed, 

 any other animals of New Holland, depart in such a manner from the ordinary char- 



' Doubts are entertained respecting tlie origin of * See O'WEN, (R.,) Marsupialia in Todil's CjtIo- 



the Dinjro, the only beast of prey of New IloUaml. pedia of Anat. and Physiol., London, 1841, 8vo., and 



- "Wateriiouse, (G. a.,) Natural History of the several elaboratf [lapers liy liiuiself and others. 



Mammalia, London, 1848, 2 vols. 8vo., vol. i., p. 4. quoted there. 



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