expressed with caution, and never, under any circumstances, positively advanced. Mr. Henderson, the respected veterinary surgeon to Her Majesty the Queen Dowager, possesses in his museum many interesting specimens of the teeth. Among the rest, he has the jaw of an animal which was ascertained to have reached the thirty-eighth year. This preparation, however, exhibits no sign that could characterize the extreme age which the horse had attained, and I allude to it, only as a confirmation of the opinion I have expressed, that, as the period of life advances, the mouth of the horse becomes more and more difficult of interpretation. 57. _The tricks, that are practised on the teeth_, are so much talked about and so generally feared, that the subject demands a few words in explanation. The breeders are known to extract the milk teeth, hoping thereby to hasten the growth of the permanent incisors, and to increase the apparent age of the colt. The gums they are likewise known to touch with the hot iron, or to freely lance for the same purpose. All of these practices are common enough; but that they accomplish the design of the persons who employ them is not at all certain. By either of these practices the animal is pained, and pain does not favour development, but, on the contrary, retards it. The suffering, however, may be brief, yet the effect does not stop there. If the milk tooth is firm in the mouth, when the attempt is made to extract it, in nineteen cases out of twenty, it will be broken and the fang left in the jaw. When the extraction of the milk teeth has been general, I have seen numbers of horses, with the broken fangs in their mouths, palpable evidences that the animals have been tampered with. But, supposing all of the tooth to be removed, nothing would be thereby gained. The permanent tooth does not push out the temporary; nor does the temporary, so directly obstruct the coming up of the permanent, as to render its presence or absence of much consequence. If the fang be removed, there may be nothing to absorb, but on that account it does not follow that there will be anything more deposited. The body of a man does not grow larger because one or more of his limbs have been amputated. On the contrary, the shock occasioned to the system by the operation, and the consequence ensuing on the loss of blood, may cause an immediate diminution of the frame. So, if a horse's tooth be drawn, the animal is alarmed, tortured--and, if the creature recovers from these effects very speedily, so that no loss of growth could be estimated, certainly the most favourable circumstances would not allow us to imagine any stimulus to development had been created. There will be some loss of blood, and this, however slight it may be, nevertheless being taken from the immediate part, must act as a local depletion. Now to deplete is to check growth by abstracting the very source of nutriment. The hemorrhage, however small,