Prof, Karl Walther, of Montevideo, has been at some pains to identify the exact spot on the bank of the Rio Negro that Darwin visited, and he has come to the conclusion that the "cliffs of Perika" are those of the Cerro de los Claveles at the confluence of the Arroyo Perico Face and the Rio Negro. The streams have here incised their channels below the level of the plains and the so-called Cerro is simply a projecting bluff overlooking the river. This locality has been marked by Prof.
Pampean clay, which was of quite a different character "déposée dans un laps de temps tres-court, comme lo résultat dune grande commotion terrestore" Darwin steadily refused to accept this hypothesis and insisted that "from whatever source and through whatever means the great Pampean formation originated, we here have unequivocal evidence of similar action at a period before that of the deposition of the marine
Text read from the printed page and cleaned; old type leaves the occasional error.