294 MAMMALS. 



tlie same species as the other. The former is almost entirely confined to the cast coast of New 

 South Wales ; but it (or at least a species) has also been taken at Swan River.* 



The ant-eating structure seems so special an adaptation,' that it is difficult to conceive that 

 all the animals in which it occurs have not sprung from one and the same source. A sujjposition 

 which receives sujsport from the horny clothing which many of them possess, — whether it takes 

 the form of quills, as in the Echidna, — scales, as in the Manis, — or harsh wiry bristles, as in 

 the Ant-eater. To show how that corresponds with the distribution of the species possessing it, 

 I have given a maj) pointing this out (Map 99). In endeavouring to trace the connexion of 

 the species with this i^roj^orty, it may jjcrhaps be more natural, seeing that the Monotremes and 

 Myrmecobius are confined to the south of Australia, to look for their communication with the 

 others rather by Africa than by New Guinea and the Indian Archipelago. But the light we have 

 to go by from living sfjecies is not much, and wc derive almost none from fossils. 



Ornithorhynchus. The long extensile glutinous tongue of the Echidna is not shared by the 

 Ornithorhynchus, or Duck-hill. It has a small flat tongue, but in other points its affinities with 

 the Echidna are sufficiently numerous. It is found in New South Wales, Van Dicman's Land, 

 Victoria, and South Australia, but not in Northern or Western Australia. 



Like the Echidna, it is a great burrower, its burrows extending for a long distance into the 

 banks where they make them. One that was opened by Mr. Bennett terminated at a distance of 

 thirty-five feet from the entrance,t and some have been found to extend as far as fifty feet in length. 



The geographical position of the Monotremes, not less than their tendency to Marsupial 

 organization and their affinity with Myrmecobius, leave little doubt that their proper station is 

 alongside the Marsupials. Those who, like Giebel, however, place them with the Edentata,^ have 

 no lack of arguments by which to support their opinion. In fact, it seems scarcely possible to 

 dispute that they are allied to both. It is an interestiag subject for specidation to endeavour to 

 ascertain which preceded the other. Is the Monotrcme the parent stock of both, or is it intermediate 

 between the Marsupials and the Edentata, — the child of the former and the parent of the latter. 

 Has the Marsupial been " born of the brooding of Echidna base" — or has it given birth to it, and 

 it in its turn given birth to the Ant-eaters ? On the one hand, we have the Monotreme so far 

 departing from the Marsupial organization, and thus seeming to take a step towards the placental ; on 

 the other hand, the organization of the Monotremes is apparently of a lower type than that of the 

 others, corresponding in more points with that of birds and reptiles, and so more likely to have first 

 appeared. But unless we are prepared to accept the Monotremes as the connecting link between 

 birds and mammals, which, seeing the wide gulph of separation between them, I imagine few 

 would be prepared to do, we are not much further advanced. 



We know nothing mammalian nearer the Birds than tlie Monotremes; but this is no proof 

 whatever, scarcely an indication, that this was the route by which the mammalian element entered 

 into existence, or even that the Mammals were derived from the Birds at all. They may have come 

 from the Reptiles. As was remarked by Waterhouse, one of the most interesting features in the skull 

 of the Marsupials, consists in the permanent separation of the bones : these do not anchylose in the 

 adult and old animals, as do many of the bones (especially those of the cranial porlion of the skull) 



* Waterhouse, "Natural History of the Marunialia." t Bennett, G., " Wanderings in New South Wales." 



Vol. I. Miirsupiata. Loudon, KS4C, p. 42. % Giebel, " Die Saugethiere," 1859, 389. 



