THE REPRODUCTIVE SYSTEM. 45 



Impregnation takes place sometimes at the first copulation, in 

 others not until the second, third, or fourth ; and in some cases I 

 have known, from decided proofs, that impregnation did not 

 ensue until the seventh warding-. Dogs should be suffered, there- 

 fore, to remain together some days, to insure prolific intercourse. 

 This protracted period, however, applies more particularly to 

 pampered and tender dogs ; those which live less artificially, as 

 sporting and rural dogs, conceive usually at the second or third 

 warding. During gestation bitches do not appear to suffer much 

 derangement of system ; some, however, appear to be listless, nau- 

 seated, and averse to particular foods ; and most of them are more 

 thirsty at this than at other times. It is not easy to detect the 

 pregnancy of a bitch until the fourth or fifth week after warding ; 

 about which time the teats enlarge, the flanks fill, and the belly as- 

 sumes a fulness and rotundity unnatural to it at others. Towards 

 the seventh week, the belly becomes pendulous, and the future in- 

 crease is not so observable as the previous. In the last week of 

 pregnancy, the contents of the belly seem to incline backwards, 

 the vulva increases in size, and a slimy matter (to soften and lu- 

 bricate the parts) often issues. 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, inter- 

 venes between the expulsion of each foetus. We have known a 

 solitary puppy appear on the seventieth day from the last inter- 

 course, and that in a case where superfoetation was improbable. 

 See Pupping. — During the pregnancy of bitches, particular care 

 should be taken to observe, and to remove, any appearance of mange 

 or other affections of the skin and surface : if this be neglected, the 

 progeny will be brought into the world with an hereditary taint 

 that no future endeavours can wholly eradicate. 



Dogs are certainly capable of superfoetation ; that is, impreg- 



female til] the venereal orgasm has entirely ceased. The clitoris of the fe- 

 male also partakes of a similar structure, and firmly retains the penis in coitu 

 by a protuberant ring which then closes firmly on it. The same structure is 

 apparent in all the canine congeners. 



