256 ESSENTIALS OF VETERINARY LAW 
jack to continue until July, the owner of the jack 
to receive five dollars for each colt, or pay at the 
rate of twenty dollars a month, when the contract 
was cancelled by agreement in May it was held 
that on the failure of the plaintiff to elect the 
method of payment the defendant might do so.’® 
A contract to pay fifty dollars for the colts of five 
mares to be put to a jack, colts or no colts, was 
held not payable until the usual weaning time of 
the colts, unless there be express agreements to 
the contrary.'® 
206. Warranty of Sound Heredity. Although 
it was stated in one case ™ that there is no implied 
warranty in the contract for the services of a stal- 
lion that the animal is free from disease which 
may be transmitted to offspring, this general con- 
clusion should not be drawn from the case in ques- 
tion. So far as is known today in science, the 
transmission of disease directly from father to 
child is extremely improbable. The father may, 
by direct contact, communicate a disease to the 
mother; and similarly the mother may communi- 
cate it to the child; but these are cases of con- 
tagion, not of heredity. But by heredity parents 
do become reproduced as to structure in the off- 
spring. Certain structural forms predispose the 
animal to definite weaknesses. Thus, with certain 
conformation of the limbs an animal is predis- 
posed toward the development of a spavin, when- 
ever the joint is put upon strain. The colt inherits 
15 Conwell v. Smith, 8 Ind. 17 Briggs v. Hunton, 87 Me. 
530. 145, 32 Atl. 794. 
16 Brown y. Mattingly, 42 Ky. 
592. 
