Notwithstanding the vast strides that science has made of late years, it is curious to note the errors and misconceptions in various points of natural history that still linger in many parts of this and other countries. We may run over a few of these popular misconceptions. Not a few even among generally well-informed people still imagine that all _Fungi_ are poisonous--including even the mushroom. Many more take it for granted that all serpents sting, and that the forked tongue is the weapon by which the 'sting' is given; the fact that it is forked seeming to afford them convincing proof of its deadly character. While there are many among the educated classes who would probably be puzzled if told, that there were other mammals besides four-footed animals and man. There are still numbers of persons who believe that a horse-hair immersed for a time in water becomes vivified and is transformed into the curious animal known as the hair-eel; and who further imagine that this, acquiring greater thickness, becomes in process of time the common eel. This belief is universal among the uneducated, at least of the rural population, in many parts of the country. Nor is it confined to them. We have heard it stoutly maintained by a very intelligent man, of good education according to the ideas of education which were generally entertained fifty or sixty years ago; his only argument was one with which, if he had not been profoundly ignorant of natural history, he could not for a moment have deceived himself. He had often seen, in ditches or in stagnant pools, a moving hair-like thing, exactly resembling a black or dark-brown hair from a horse's mane, and no doubt it was a living thing, _and an eel_! And the other day we read among the answers to correspondents in a weekly paper, a very good advice to one who had directed attention to this same marvel--to try the experiment for himself with a horse-hair. But for any one who seeks information in the proper quarter, there is no need of such experiment; and the needful information is easily obtained. A few hours spent in the perusal of a book or two of natural history would make any man of common-sense ashamed that he had ever for a moment credited such an absurdity. The natural history of the eel is well known; and at no stage of its existence is it in form and appearance like the hair-eel. The natural history of the creature called by this name--the _Gordius_ of naturalists--is also known. It is not a fish like the eel; it belongs to a class of parasitic worms very far below fishes in the scale of creation. It has no relation either to the eel or to a horse-hair. Yet the ploughman looks upon it with wonder, as he thinks of what he believes to be its origin; and the boys of the village school, when they find it in the gutter by the roadside or millpond, gather around it to gaze, and assure themselves by ocular observation of the truth of what they have heard. Ought they not to hear in the