as the Congo negroes, but are, on the contrary, rather haughty. One morning I came upon a cluster of them in the market breakfasting after their work was done, and I stopped to talk with them, asking what they had for breakfast, and trying various subjects on which to open an acquaintance. But they looked at me coldly and suspiciously, barely answering my questions, and were evidently relieved when I walked away. [Illustration: Mina Negress and Child.] _May 26th._—Tijuca. In the pleasant environs of Rio there is no resort more frequented than the establishment of Mr. Bennett at Tijuca, and we were not sorry the day before yesterday to leave the hot, dusty city, with a pleasant party of friends, for this cluster of mountains, some eighteen hundred feet above the sea level and about eight miles from Rio. It takes its name from the peak of Tijuca, so conspicuous an object in the coast range. On our arrival we were very cordially welcomed by our host himself, who was not quite a stranger to us, for Mr. Agassiz has been already indebted to him for valuable collections. Mr. Bennett has an Englishman’s love of nature, and is very familiar with the botany and zoölogy of the beautiful region which has been his home for many years. Under his guidance, we have taken a number of pleasant rambles and rides, regretting only that we cannot avail ourselves for a longer time of his intimate knowledge of the locality and its productions. I have alluded before to the perplexing character of the geology, and the almost universal decomposition of the rock surfaces, making it difficult to decipher them. The presence of the drift phenomena, so universal in the Northern hemisphere, has been denied here; but, in his long walk to-day, Mr. Agassiz has had an opportunity of observing a great number of erratic boulders, having no connection with the rocks in place, and also a sheet of drift studded with boulders and resting above the partially stratified metamorphic rock in immediate contact with it. I introduce here a letter written by him to his friend, Professor Peirce of Harvard University, under the first impression of the day’s experience, which will best explain his view of the subject. “May 27th, 1865, TIJUCA. “MY DEAR PEIRCE:—