Meanwhile one daily anxiety embittered his scientific happiness. The small means at his command could hardly be made, even with the strictest economy, to cover the necessary expenses of himself and his artist, in which were included books, drawing materials, fees, etc. He was in constant terror lest he should be obliged to leave Paris, to give up his investigations on the fossil fishes, and to stop work on the costly plates he had begun. The truth about his affairs, which he would gladly have concealed from those at home as long as possible, was drawn from him by an accidental occurrence. His brother had written to him for a certain book, and, failing to receive it, inquired with some surprise why his commission was neglected. Agassiz's next letter, about a month later than the one to his uncle, gives the explanation. TO HIS BROTHER. PARIS, March, 1832. . . .Here is the book for which you asked me,--price, 18 francs. I shall be very sorry if it comes too late, but I could not help it . . .In the first place I had not money enough to pay for it without being left actually penniless. You can imagine that after the fuel bill for the winter is paid, little remains for other expenses out of my 200 francs a month, five louis of which are always due to my companion. Far from having anything in advance, my month's supply is thus taken up at once. . .Beside this cause of delay, you can have no idea what it is to hunt for anything in Paris when you are a stranger there. As I go out only in two or three directions leading to my work, and might not otherwise leave my own street for a month at a time, I naturally find myself astray when I am off this beaten track. . .You have asked me several times how I have been received by those to whom I had introductions. Frankly, after having delivered a few of my letters, I have never been again, because I cannot, in my position, spare time for visits. . . Another excellent reason for staying away now is that I have no presentable coat. At M. Cuvier's only am I sufficiently at ease to go in a frock coat. . .Saturday, a week ago, M. de Ferussac offered me the editorship of the zoological section of the "Bulletin;" it would be worth to me an additional thousand francs, but would require two or three hours' work daily. Write me soon what you think about it. In the midst of all the encouragements which sustain me and renew my ardor, I am depressed by the reverse side of my position. This letter drew forth the following one. FROM HIS MOTHER. CONCISE, March, 1832.