16 



in Turin, in which he gave it as his opinion that human and bovine 

 tuberculosis are identical, because they have the closest anatomical 

 affinity ; and Dr. Johne states that nearly all the authorities admit the 

 identity in construction of the tubercles in man and the lower animals. 



IS BOVINE TUBERCULOSIS HP:REDrrARY? 



From the earliest times many have believed that bovine tuberculosis 

 is hereditary, while others have strongly doubted it. It has been 

 repeatedly observed that calves and ^)igs born of tuberculous parents 

 became affected sooner or later with the disease, and many cases have 

 been reported of persons suffering heavy losses because of employing 

 tuberculous animals for breeding purposes, and finally getting rid of 

 the scourge, by disposing of all their infected animals, and obtaining 

 others which were free from all suspicion of taint. 



In the outbreak of tuberculosis in the herd on the State College 

 farm in Maine, already referred to, there were calves slaughtered, 

 which were scarcely a month old, but which were plainly affected with 

 the disease. 



Zippelius, in 1876, published a remarkable case proving the trans- 

 mission of the disease by the male. He states that a stock-breeder 

 wliose herd had shown no signs of tuberculosis for more than twelve 

 vears, purchased a bull that proved to be affected with this disease, 

 and was therefore killed, and all the animals sired by this bull had 

 to be slaughtered when they reached adult age, because of tuberculo- 

 sis which developed in them at that period. 



The writings of Chauveau, Esser, Semmer and many others give 

 numerous cases illustrating the heredity of this disease. 



Dr. Johne, of the Dresden Veterinary School, found an eight 

 months foetus taken from a tuberculous cow, to be affected with the 

 disease. The placenta and uterus showed no visible signs of the 

 disease, but in the lower lobe of the right lung a tubercle as large as 

 a pea was detected containing the characteristics of the disease. The 

 bronchial glands and also the liver were affected, and microscopical 

 examinations revealed the tuberculous bacilli. This case puts the 

 question of inheritance beyond all doubt. 



It is a notable fact that tuberculous cows are very liable to abortion, 

 and it is quite probable that, in such cases, the foetus is attacked and 

 killed by the disease, and the abortion is the consequence. 



An opinion prevails very generally that animals descended from 



