Many of them, however, are modified from the Guiana type, and about one-seventh seem to be restricted to Para.These endemic species are not highly peculiar, and they may yet be found over a great part of Northern Brazil when the country is better explored.They do not warrant us in concluding that the district forms an independent province, although they show that its Fauna is not wholly derivative, and that the land is probably not entirely a new formation.From all these facts, I think we must conclude that the Para district belongs to the Guiana province and that, if it is newer land than Guiana, it must have received the great bulk of its animal population from that region.I am informed by Dr.Sclater that similar results are derivable from the comparison of the birds of these countries."One of the most interesting excursions made by Mr.Bates from Para was the ascent of the river Tocantins--the mouth of which lies about 4-5 miles from the city of Para.This was twice attempted.On the second occasion--our author being in company with Mr.Wallace--the travellers penetrated as far as the rapids of Arroyos, about 130 miles from its mouth.This district is one of the chief collecting-grounds of the well-known Brazil-nut (Bertholletia excelsa), which is here very plentiful, grove after grove of these splendid trees being visible, towering above their fellows, with the "woody fruits, large and round as cannon-balls, dotted over the branches." The Hyacinthine Macaw (Ara hyacinthina) is another natural wonder, first met with here.This splendid bird, which is occasionally brought alive to the Zoological Gardens of Europe, "only occurs in the interior of Brazil, from 16' S.L.to the southern border of the Amazon valley." Its enormous beak--which must strike even the most unobservant with wonder--appears to be adapted to enable it to feed on the nuts of the Mucuja Palm (Acrocomia lasiospatha).
"These nuts, which are so hard as to be difficult to break with a heavy hammer, are crushed to a pulp by the powerful beak of this Macaw."Mr.Bates' later part is mainly devoted to his residence at Santarem, at the junction of the Rio Tapajos with the main stream, and to his account of Upper Amazon, or Solimoens--the Fauna of which is, as we shall presently see, in many respects very different from that of the lower part of the river.At Santarem--"the most important and most civilised settlement on the Amazon, between the Atlantic and Para "--Mr.Bates made his headquarters for three years and a half, during which time several excursions up the little-known Tapajos were effected.
Some 70 miles up the stream, on its affluent, the Cupari, a new Fauna, for the most part very distinct from that of the lower part of the same stream, was entered upon."At the same time a considerable proportion of the Cupari species were identical with those of Ega, on the Upper Amazon, a district eight times further removed than the village just mentioned." Mr.Bates was more successful here than on his excursion up the Tocantins, and obtained twenty new species of fishes, and many new and conspicuous insects, apparently peculiar to this part of the Amazonian valley.
In a later chapter Mr.Bates commences his account of the Solimoens, or Upper Amazons, on the banks of which he passed four years and a half.The country is a "magnificent wilderness, where civilised man has, as yet, scarcely obtained a footing-the cultivated ground, from the Rio Negro to the Andes, amounting only to a few score acres." During the whole of this time Mr.
Bates' headquarters were at Ega, on the Teffe, a confluent of the great river from the south, whence excursions were made sometimes for 300 or 400 miles into the interior.In the intervals Mr.
Bates followed his pursuit as a collecting naturalist in the same "peaceful, regular way," as he might have done in a European village.Our author draws a most striking picture of the quiet, secluded life he led in this far-distant spot.The difficulty of getting news and the want of intellectual society were the great drawbacks--"the latter increasing until it became almost insupportable." "I was obliged at last," Mr.Bates naively remarks, "to come to the conclusion that the contemplation of Nature, alone is not sufficient to fill the human heart and mind." Mr.Bates must indeed have been driven to great straits as regards his mental food, when, as he tell us, he took to reading the Athenaeum three times over, "the first time devouring the more interesting articles--the second, the whole of the remainder--and the third, reading all the advertisements from beginning to end."Ega was, indeed, as Mr.Bates remarks, a fine field for a Natural History collector, the only previous scientific visitants to that region having been the German Naturalists, Spix and Martius, and the Count de Castelnau when he descended the Amazons from the Pacific.Mr.Bates' account of the monkeys of the genera Brachyuyus, Nyctipithecus and Midas met with in this region, and the whole of the very pregnant remarks which follow on the American forms of the Quadrumana, will be read with interest by every one, particularly by those who pay attention to the important subject of geographical distribution.We need hardly say that Mr.Bates, after the attention he has bestowed upon this question, is a zealous advocate of the hypothesis of the origin of species by derivation from a common stock.After giving an outline of the general distribution of Monkeys, he clearly argues that unless the "common origin at least of the species of a family be admitted, the problem of their distribution must remain an inexplicable mystery." Mr.Bates evidently thoroughly understands the nature of this interesting problem, and in another passage, in which the very singular distribution of the Butterflies of the genus Heliconius is enlarged upon, concludes with the following significant remarks upon this important subject:
