GEOGBAPHT OF THE MALAY AECIIIPELAGO. 183 



tinent, it is still au impassable barrier against the passage of any 

 considerable number and variety of land animals ; and that in all 

 cases in wliicli sucli islands possess a tolerably rich and varied 

 fauna of species mostly identical, or closely allied with those of 

 the adjacent country, we are forced to the conclusion that a geo- 

 logically recent disruption has taken place. Great Britain, Ire- 

 land, Sicily, Sumatra, Java and Borneo, the Aru Islands, the 

 Canaries and Madeira, are cases to which the reasoning is fully 

 appKcable. 



lu his introductory Essay on the Plora of New Zealand, Dr. 

 Hooker has most convincingly applied this principle to show the 

 former connexion of New Zealand and other southern islands with 

 the southern extremity of America; and I will take this opportunity 

 of calling the attention of zoologists to the very satisfactory man- 

 ner in. which this view clears away many difficulties in the distri- 

 bution of animals. The most obvious of these is the occurrence 

 of Marsupials in America only, beyond the Australian region. 

 They evidently entered by the same route as the plants of New 

 Zealand and Tasmania which occur in South temperate America, 

 but having greater powers of dispersion, a greater plasticity of 

 organization, have extended themselves over the whole continent 

 though with so few modifications of form and structure as to point 

 to a unity of origin at a comparatively recent period. It is among 

 insects, however, that the resemblances approach in number and 

 degree to those exhibited by plants. Among Butterflies the beau- 

 tifid Helicomdcs are strictly confined to South America, with the 

 exception of a single genus {Hamadrt/as) found in the Australian 

 region from New Zealand to New Guinea. In Coleoptera many 

 families and genera are characteristic of the two countries ; such 

 are PseudomorphidcB among the Geodephaga, La/mprimidce and 

 Syndesidce among the Lucani, Anoplognathidcv among the Lamel- 

 licornes, StigmoderidcB among the Buprestes, Natalis among the 

 Cleridse, besides a great number of representative genera. This 

 peculiar distribution has hitherto only excited astonishment, and 

 has confounded all ideas of unity in the distribution of organic 

 beings ; but we now see that they are in exact accordance with the 

 phenomena presented by the flora of the same regions, as developed 

 in the greatest detail by the researches of Dr. Hooker. 



It is somewhat singular, however, that not one identical species 

 of insect should yet have been discovered, while no less than 89 

 species of flowering plants are found both in New Zealand and 

 South America. The relations of the animals and of the plants 



