BREEDING IN BITCHES. 91 



cases I have 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. During gestation, dogs do not appear 

 to suffer much derangement of system ; some, how^ever, ap- 

 pear to be listless, nauseated, and averse to particular foods ; 

 and most of them are more thirsty at this than at other times. 

 It is not easy to detect whether bitches are in pup until the 

 fourth or fifth week after warding: about this time the teats 

 enlarge, the flanks fill, and the belly assumes a roundness 

 unnatural to it at others. About the seventh week, the 

 belly becomes pendulous, and the future increase 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, intervenes between each young one. I have 

 known a solitary puppy appear on the seventieth day from 

 the last intercourse, and that in a case where superfoetation 

 was improbable. — See Pupping. 



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

 pregnation may take place at more than one warding, and 

 that by distinct mates. The fact was long ago admitted by 

 naturalists and physiologists * ; since which time numerous 

 circumstances have fallen under the notice of sportsmen that 

 confirm the matter. I have, in several instances, seen whelps 



* In t'e superfcEtation of brutes, is there not reason to suppose that the 

 germ is contributed from each ovaria iu succession? or do the ova or germs 

 present themselves indiscriminately from both ? The interesting experiments 

 of Dr. Haighton, related in the Philosophical Transactions^ 1797 ^ p. 159; 

 and by Mr. Cruickshanks, ib. p. 197, tend to throw light on this curious 

 subject, 



Superfoetation seems extended also to the human 5 instances of this are re- 

 corded in Blumenbach's Institutions of Physiology^ and in White's work on 

 the Regular Gradation of the Human Race. 



G2 



