This anticipation was more than confirmed by the result of the journey. It is true that Mr. Agassiz did not go beyond the Peruvian frontier, and therefore could not verify his prophecy in that region. But he found the localization of species in the Amazons circumscribed within much narrower limits than he expected, the whole length of the great stream, as well as its tributaries, being broken up into numerous distinct faunæ. There can be no doubt that what is true for nearly three thousand miles of its course is true also for the head-waters of the Amazons; indeed, other investigators have already described some species from its higher tributaries differing entirely from those collected upon this expedition. Footnote 7: Mr. Agassiz afterward visited these hills himself, and an account of their structure and probable origin will be found in the chapter on the physical history of the Amazons. Footnote 8: See Appendix No. II. Footnote 9: It proved in the sequel unnecessary to seek the glacial phenomena of tropical South America in its highest mountains. In Brazil the moraines are as distinct and as well preserved in some of the coast ranges on the Atlantic side, not more than twelve or fifteen hundred feet high, as in any glaciated localities known to geologists in more northern parts of the world. The snow line, even in those latitudes, then descended so low that masses of ice formed above its level actually forced their way down to the sea-coast.—L. A. Footnote 10: In copying the journal from which these notes are taken, I have hesitated to burden the narrative with anatomical details. But for those who take an interest in such investigations it may be well to add here that the frog, when first hatched, is simply an oblong body, without any appendages, and tapering slightly towards its posterior end. In that condition it resembles the Cecilia. In its next stage, that of the tadpole, when the extremity has elongated into a tail, the gills are fairly developed, and it has one pair of imperfect legs, it resembles the Siren, with its rudimentary limbs. In its succeeding stages, when the same animal has two pairs of legs and a fin around the tail, it recalls the Proteus and Menobranchus. Finally the gills are suppressed, the animal breathes through lungs, but the tail still remains; it then recalls Menopoma and the Salamanders. At last the tail shrinks and disappears, and the frog is complete. This gives us a standard by which the relative position of the leading groups of the class may safely be determined.—L. A. Footnote 11: