picture of past times, with the image of which our minds had been filled for the last few days in consequence of the glacial phenomena constantly presented to us on our journey. _July 6th._—To-morrow was to have been the day of our departure for the Amazons, but private interests must yield to public good, and it seems that the steamer which was to have left for Pará to-morrow has been taken by the government to transport troops to the seat of war. The aspect of the war grows daily more serious, and the Emperor goes himself the day after to-morrow to Rio Grande do Sul, accompanied by his son-in-law, the Duke of Saxe, soon to be followed by the Conte d’Eu, who is expected by the French steamer of the 18th of this month. Under these circumstances, not only are we prevented from going at the appointed date, but it seems not improbable that the exigencies of war may cause a still further delay, should other steamers be needed. A very pleasant public dinner, intended to be on the eve of his departure, was given to Mr. Agassiz yesterday by Messrs. Fleiuss and Linde. Germans, Swiss, French, Americans, and Brazilians made up the company, a mingling of nationalities which resulted in a very general harmony. _July 9th._—For some time Mr. Agassiz has been trying to get living specimens of the insect so injurious to the coffee-tree; the larva of a little moth akin to those which destroy the vineyards in Europe. Yesterday he succeeded in obtaining some, and among them one just spinning his cocoon on the leaf. We watched him for a long time with the lens as he wove his filmy tent. He had arched the threads upwards in the centre, so as to leave a little hollow space into which he could withdraw; this tiny vault seemed to be completed at the moment we saw him, and he was drawing threads forward and fastening them at a short distance beyond, thus lashing his house to the leaf as it were. The exquisite accuracy of the work was amazing. He was spinning the thread with his mouth, and with every new stitch he turned his body backward, attached his thread to the same spot, then drew it forward and fastened it exactly on a line with the last, with a precision and rapidity that machinery could hardly imitate. It is a curious question how far this perfection of workmanship in many of the lower animals is simply identical with their organization, and therefore to be considered a function, as inevitable in its action as digestion or respiration, rather than an instinct. In this case the body of the little animal was his measure: it was amazing to see him lay down his threads with such accuracy, till one remembered that he could not make them longer or shorter; for, starting from the centre of his house, and stretching his body its full length, they must always reach the same point. The same is true of the so-called mathematics of the bee. The bees stand as close as they can together in their hive for economy of space, and each one