208 BOARD OF AGRICULTURE. 



If we iiKjuire fiutlier into the causes of the increased susceptibility 

 to the infection, as seen more especially in our thoroughbred stock, 

 we shall lind that hereditv and multiplied consanguinity play no 

 menial part. Any physical weakness which the sire or dam may 

 possess is liable to be transmitted to the immediate progen}', but if 

 one generation escapes, the trouble ma}' appear in the next, in ac- 

 cordance with the well-established principle of atavism. Diseased 

 conditions are also inherited ; and I believe that there is no predis- 

 posing cause which exercises such a poteut influence in the produc- 

 tion of tuberculosis as the pernicious system of in-and-in breeding. 

 Thus from parent to offspring, from one generation to another, we 

 often see the fatal tendenc}' transmitted in unbroken succession, and 

 the more complicated the relationship becomes, the greater is the 

 virulence of the resulting products. In spite, therefore, of the many 

 palpable examples of this broken law, some breeders still pursue, 

 year by year, the suicidal policy of clinging to one strain, regardless 

 of the impending consequences. 



Hence this insidious and maliofnant maladv, soon to be recoornized 

 as the dreaded scourge of our land, is now being disseminated in 

 everv direction through the consanoruineous infection of our thor- 

 oughbred stock. And Prof. James Law, F. R. C. V. S., of Cornell 

 University, in alluding to this subject, says, ''That the esteemed 

 qualities have been preserved, strengthened and increased in this 

 way there can be no doubt, but there can be just as little doubt that 

 any inherited weakness or disease has been often transmitted and 

 even intensified. I could meution particular families in our highest- 

 priced breeds in which tuberculosis has become a fixed character ;" 

 and further on he observes that "excessive weakness and stupidity 

 of the 3'oung is another common result of in-breeding."* 



CONTAGIOUS BY COI^TACT. 



The observations of Dr. Grad, veterinary surgeon at Wasselonne, 

 Alsace, on the spread of this disease by contaminated stalls, are 

 very conclusive. On different occasions owners had informed him 

 that the}' had lost several animals from consumption in the same stall. 

 At first he did not attach much importance to the matter, but one 

 day, when visiting the stables of an extensive farmer in Leinheim, 



*Report of Am. Public Health Association, New York, 1875, vol. 2, page 250. 



