By and by the boys wanted to own books which would tell them about birds, fishes, and rocks. These were the things Louis was thinking of all the time. The boys saved every cent of their spending money for these books. They were always talking about animals. One day, as they were walking from Zurich to Motier, they were overtaken by a gentleman in a carriage. He asked them to ride with him and to share his lunch. They did so and talked to him about their studies. He was greatly taken with Louis, who was a handsome, graceful lad, as he told the stranger his fondness for books. The gentleman hardly took his eyes from the boy, and a few days later Reverend Mr. Agassiz had a letter from him saying that he was very rich and that he wanted to adopt Louis. He said he was sure that the boy was a genius. Louis was not willing, though, to be any one's boy but his own parents', and so the matter was dropped. The boys did not have much spending money, and it took, oh, such a long time to save enough to buy even one book! So they often went to a library, or borrowed a book from a teacher, then copied every word of it with pen and ink, so as to own it. You can see from this that they were very much in earnest. When not studying or copying, the brothers were busy outdoors, watching animals. In this way they learned just what kinds of fishes could be found in certain lakes, and almost the exact day when different birds would come or go from the woods. In their rooms the cupboards and shelves were crammed with shells, stuffed fishes, plants, and odd specimens. On the ledges of the windows hovered often as many as fifty kinds of birds who had become tamed and who made their home there. At seventeen Louis was bending over his desk a good many hours of the day. He learned French, German, Latin, Greek, Italian, and English. But he was wise enough to keep himself well and strong by walking, swimming, and fencing. Because Louis's parents and his uncle wanted him to be a doctor, he studied medicine. He carried home his diploma when he was twenty-three and earned a degree in philosophy, too. But in his own heart he knew he would not be happy unless he could hunt the world over for strange creatures and try to find out the secrets of the old, old mountains. Louis traveled all he could and became so excited over the different things he discovered that he sometimes stopped in cities and towns and talked to the people, in their public halls, about them. He had a happy way of telling his news, and crowds went to listen to the young Swiss. The King of Prussia thought that any one who used his eyes in such good fashion ought to visit many places. He said to Louis: "Here is money for you to travel with, so that you may find out more of these strange things. You are a clever young man and can do much for the world!"