Some tropical spiders are of very great size, so that, in Brazil, children sometimes tie one end of a piece of string round their waist, and lead them about as if they were dogs. This does not mean, of course, that they are quite so big as dogs—even little ones—but the legs of a very huge mygale, as these monsters are called, might have a spread as big as a man’s hand, and the body would be then, perhaps, not so very much smaller than a mouse’s. That the webs made by such immense spiders as these should be strong enough to hold a small bird, and that, when caught, the bird should be eaten as flies are by spiders here at home, does not seem so very remarkable—in fact, it is just what one might reasonably expect. [Illustration: CURIOUS PETS. Brazilian children tie one end of a piece of string round the waist of Mygales and lead them about as if they were dogs.] But naturalists, for the most part, are a very unimaginative, sceptical set of men, with whom not to believe a thing, if it is, in the smallest degree, striking or picturesque, is a sort of virtue, in which they hug themselves as long as they can. Accordingly, when Madame Merian and Palisot de Beauvois told them that these large spiders really did eat birds, they all set their faces against it, and were determined not to credit an account derived from the reports of natives, who, of all people in the world, were thought the least likely to know anything about the animals which lived in their own country. It is strange how this idea—or some other one which comes to practically the same thing—prevails. It is as strong to-day as ever, yet in ninety-nine cases out of a hundred, what the natives say turns out to be true. At last some European happens to see, once, what they have seen and known all their lives. Then, perhaps, the natives are believed, but only, as it were, in the wake of the one European, who gets more credit for finding they were right than they do for having always told the truth. The one European, in this instance, was Mr. H. W. Bates, who, in his well-known work _The Naturalist on the River Amazon_, gives the following account of what he saw: “At Cameta I chanced to verify a fact relating to the habits of a large hairy spider of the genus Mygale, in a manner worth recording. The species was _M. avicularia_, or one very closely allied to it. The individual was nearly two inches in length of body, but the legs expanded seven inches, and the entire body and legs were covered with coarse grey and reddish hairs. I was attracted by a movement of the monster, on a tree-trunk; it was close beneath a deep crevice in the tree, across which was stretched a dense, white web. The lower part of the web was broken, and two small birds—finches—were entangled in the pieces; they were about the size of the English siskin, and I judged the two to be male and female. One of them was quite dead, the other lay under the body of the spider, not