ij4] TYPES OF ORGANIZATION. 177 



on the 90-feet plain, I found half the skeleton of the 

 Macrauchenia Patachonica a remarkable quadruped, full 

 as large as a camel. It belongs to the same division of 

 the Pachydermata with the rhinoceros, tapir, and palaeo- 

 therium ; but in the structure of the bones of its long neck 

 its shows a clear relation to the camel, or rather to the 

 guanaco and llama. From recent sea-shells being found 

 on two of the higher step-formed plains, which must have 

 been modelled and upraised before the mud was deposited 

 in which the macrauchenia was intombed, it is certain 

 that this curious quadruped lived long after the sea 

 was inhabited by its present shells. I was at first much 

 surprised how a large quadruped could so lately have 

 subsisted, in lat. 49° 15', on these wretched gravel plains 

 with their stunted vegetation ; but the relationship of the 

 macrauchenia to the guanaco, now an inhabitant of the most 

 sterile parts, partly explains this difficulty. 



The relationship, though distant, between the macrau- 

 chenia and the guanaco, between the toxodon and the 

 capybara — the closer relationship between the many extinct 

 Edentata and the living sloths, ant-eaters, and armadillos, 

 now so eminently characteristic of South American zoology — 

 and the still closer relationship between the fossil and living 

 species of Ctenomys and Hydroch(BruSy are most interest- 

 ing facts. This relationship is shown wonderfully — as 

 wonderfully as between the fossil and extinct marsupial 

 animals of Australia — by the great collection lately brought 

 to Europe from the caves of Brazil by MM. Lund and 

 Clausen. In this collection there are extinct species of all 

 the thirty-two genera, excepting four, of the terrestrial 

 quadrupeds now inhabiting the provinces in which the 

 caves occur ; and the extinct species are much more 

 numerous than those now living : there are fossil ant- 

 eaters, armadillos, tapirs, peccaries, guanacos, opossums, 

 and numerous South American gnawers and monkeys, and 

 other animals. This wonderful relationship in the same 

 continent between the dead and the living, will, I do not 

 doubt, hereafter throw more light on the appearance of 

 organic beings on our earth, and their disappearance from 

 it, than any other class of facts. 



It is impossible to reflect on the changed state of the 

 American continent without the deepest astonishment. 

 Formerly it must have swarmed with great monsters: 

 now we find mf^f pif^mics, rotiipared with the iinft-f>Mlent, 



