Hereditary Diseases of Sheep and Piys. 
23 
immediate produce of such a cross is not only defective itself, 
but all the future progeny of the same female is apt to be defec- 
tive likewise, and to partake of the characteristics of the faulty 
male, especially if he be the one with which she has first had 
fruitful intercourse. Numerous examples, both among the human 
species and among the lower animals, might be given to illus- 
trate this curious fact. Women married for the second time 
frequently have children which bear a striking resemblance to the 
first husband, both in physical and mental development, as well 
as in defects and diseases ; for, as has been already remarked, 
resemblance in anatomical and physiological characters is ever 
accompanied by resemblance in pathological characters. Every 
one is familiar with the well-known case of Lord Morton's 
chestnut mare of pure Arab breed, which had a foal by a quagga, 
or wild ass, and whose subsequent foals by Arabian and 
thorough-bred horses still resembled the quagga foal in the 
peculiar stripes along the head and back and in the stiff, straight, 
upright mane.* Delabere Blaine mentions several illustrative 
cases occurring among dogs,t and also a case of a black and 
white sow, which had pigs to a wild boar of a deep chestnut 
colour, and had afterwards, by different boars of the Essex breed, 
several litters which resembled the progeny of the wild boar in 
colour and general appearance. These facts have been variously 
accounted for. 1st. A permanent influence is believed to be 
exercised on all the ova of the female by the semen of the first 
male — an opinion entertained by Haller and several other 
eminent physiologists. 2nd. The first foetus, possessing of course 
the prominent characters of the first male, is believed to produce 
a kind of inoculation of the female. The blood of the foetus 
passes by the placental circulation into the blood of the mother, 
and there produces changes of a more or less permanent kind, 
which are propagated, along with her own proper characters, to 
each subsequent progeny, whether by the same or by different 
males. This view has recently been ably propounded by Dr. 
Alexander Harvey,j and appears to afford very satisfactory 
explanation of the cases above mentioned. 3rd. The resem- 
blance which the offspring of the same mother by different males 
often has to the offspring of the male with which she first 
had fruitful intercourse has been supposed to depend on the 
imagination of the female, and her continued recollection of 
her first mate and her first offspring. This, though a very 
* Rural Cyclopaedia. Blaine's Veterinary Art, p. 244. 
+ Blaine's Canine Patliology. Fourth Edition, pp. 46, 47. 
X Edinburgh Monthly Medical Journal for October, 1849, and for October and 
November, 1S50; and his pamphlet ' On a. remarkable Efi'ect of Cross-breeding.' 
Edin. 1851. 
