It may be of interest to remark that the fang of the baby viper found loose in its mouth does not resemble those remaining, either in form or structure. That it cannot be a jaw tooth is evident from its size. Jaw and palate teeth there are, but discernible only to the touch, and under a magnifying glass. The fixed fang from the side on which I found this loose one, is a trifle shorter, and much finer than its fellow. In the loose one here given I can hardly discern any involution at all, but on touching it with the inky point of a fine needle, the stain shows it be hollow, and clearly so, at its base. In the two fixed fangs, however, the involution is so incomplete that, minute as they are, the point of a very fine needle can be drawn all down them without slipping off. One of them, the larger, on being touched with ink, revealed this open groove or incomplete involution so distinctly that I tried the other and was convinced at once. The loose one may be a first and only half-developed fang. They are almost as transparent as glass. I requested the keeper to look into the mouths of those subsequently dead, but he found no other loose fangs. Of the remaining forty-five deceased, let us hope those into whose hands they have fallen will be able to throw some further light on the development of fangs in very young vipers. Fayrer tells us that a young cobra is not venomous until it has cast its first skin, which is usually within a fortnight. White of Selborne found no trace of fangs in young vipers which he examined with a lens; but these had not yet been born. The possible cause of functional development in this little viper’s fangs may be found in chap. xxiv. of this work.