BISHOP, _v._ _To bishop a horse_, is to remove, by filing, the distinguishing marks by which the teeth indicate the age. It was a very common practice some years since, and is still resorted to by low horse dealers. It will, however, by carefully observing other indiciæ of age, be easily detected. See AGE OF HORSE. BISTORT, _s._ A plant called snake-weed. The roots are a very powerful astringent. It has also styptic properties. BISTOURY, _s._ A surgeon’s instrument, used in making incisions. BIT, _s._ The iron part of the bridle which is put into the horse’s mouth. BIT, _v._ To put the bridle upon a horse. BITCH, _s._ The female of the dog kind. Bitches should be allowed to breed, nor is it good for their health to prevent it; for nature almost invariably punishes extraordinary deviations from her established laws, of which the reproductive system is one of the most important. Breeding, therefore, is so much a healthy and necessary process, that bitches prevented from it rarely remain unaffected by disease. Bitches in heat are very cunning, and often elude all but the greatest vigilance in their attempts to escape in search of a mate; and thus, for want of due caution, many frustrate the hopes of their owners in the desired breed; and many others meet their death by becoming lined by a dog so extremely disproportionate in size that the mothers are found unable to bring forth. Impregnation takes place sometimes at the first copulation, in others not until the second, third, or fourth; and in some cases it has been known, from decided proofs, that impregnation did not ensue until the seventh warding. Dogs should be suffered, therefore, to remain together some days to insure prolific intercourse. It is not easy to detect whether bitches are in pup until the fourth or fifth week after warding; about which time the teats enlarge, the flanks fill, and the belly assumes a fulness and rotundity unnatural to it at others. Pupping usually comes on the sixty-second, sixty-third, or, at farthest, on the sixty-fourth day. A quarter or half an hour, and sometimes a longer time, intervenes between the expulsion of each fœtus. Dogs are certainly capable of superfœtation; that is, impregnation may take place at more than one warding, and that by distinct mates.