2i3 AUSTRALIAN AND TASMANIAN ANIMALS 



zoogeographic boundary," and that nearly the entire eastern half of the archipelago 

 must be regarded as a transition area between the Oriental and Australian regions, 

 the boundaries of which cannot be denned. After reference to the theory that 

 the Australian fauna came from South America, it is concluded " that in post- 

 Cretaceous times (that is to say, the epoch succeeding the one in which the chalk 

 was deposited, or, in other words, the Tertiary period) there was a broad 

 connection between the three Greater Sunda Islands — Java, Borneo, and 

 Sumatra — and the mainland of Asia on the one hand, and between New Guinea 

 and Australia on the other ; and that between the Sunda Islands and New 

 Guinea a connection must have existed, which was really less easy to pass over." 

 Celebes is considered to possess an impoverished Indian fauna, due to the absence 

 of free connection with the larger western isles, this poverty being most noticeable 

 in the case of fishes. Its fauna may be the result of the consolidation of smaller 

 islands, which were supplied by feeding lines from islands to the south, north, and 

 east. " It is strange that the truly Indian character of Celebes remained 

 unsuspected so long; while, on the other hand, no one doubted, but rather laid 

 stress upon, the Australian relationship of that vast easterly island, New Guinea., 

 the fauna of which is fully as Indian as that of Celebes is Australian." 



Taking, then, New Guinea and some of the smaller islands in its neighbour- 

 hood as the western limits of the Australian realm, reference may be made in the 

 first place to some of the physical features of Australia and Tasmania, which form 

 the typical portion of that realm. As regards Australia itself, the coast-line in 

 the neighbourhood of Cape York lies within the limits of the tropical rain-belt ; 

 while a strip of coast trending in a southerly direction from Brisbane almost to 

 the latitude of Melbourne is likewise included in the rainy zone, as is also 

 Tasmania. In north-eastern Australia the rain-belt follows the line of the coast 

 to die out among wooded and then grassy plains. We then come upon a desert 

 tract extending along the southern border of the Great Australian Bight, and 

 thence following the coast in a north-westerly direction till the West Australian 

 area of hard-leaved trees is reached. Over a part of the western border this 

 expands into a kind of semi-desert, which includes nearly one-half of the entire 

 continent. Although the vegetation of the rain-belt is less luxuriant than that of 

 the Malay Islands, yet, allowing for the difference in the species to be met with in 

 the two areas, there is a very considerable resemblance. On the other hand, that 

 portion of the rainy area which lies within the southern temperate tract on the 

 south-eastern coast of Australia and including Tasmania is of an altogether 

 characteristic and peculiar type ; this being especially the case with the wooded 

 ravines of Victoria, locally known as fern-gullies, which owe their wonderful 

 luxuriance more to moisture in the ground than to that which falls from above. 

 In this area the forest over extensive tracts is divisible into distinct zones, of which 

 the uppermost is in some instances composed of closely approximated eucalyptus 

 trees, while in others it consists of more widely separated trees of the same group, 

 some of which tower to a height of between 250 and 350 feet. The tree-ferns of 

 the lower zone do not, on the other hand, exceed a height of from 35 to 45 feet. 

 It should be added that ferns recalling in general appearance the European 

 Osmunda, or royal fern, often cover the ground over large tracts of the forest ; 



