114 BuivLETiN 65. 



aeration. The final result is as if the air contained little oxygen, 

 in other words, as in the case of a close building without any 

 means of renewing the air. 



d. Insufficient or Unwholesome Food. Overtaxing . 



lyack of food, and indigestible, or innutritions food, agree in 

 producing practical starvation and weakness with increased sus- 

 ceptibility to tuberculosis. Hence, this disease is the scourge of 

 the half starved poor, and no less of the rich who abuse their 

 digestive organs, and court chronic dyspepsia. So, too, in our 

 dairy herds the stimulating ratioa-for-milk, the warm drinking 

 water, and warm atmosphere, together with the enforced rest in 

 the stalls for months at a time, and the clean, careful milking 

 soliciting the gland to act to its extreme capacity, all tend to a 

 lowering of the general health and an increased susceptibility. 

 This sufi&ciently illustrates how the cow which has been made a 

 milking machine, and which to this end must produce a calf 

 every year, becomes dangerously susceptible to any tubercle 

 bacillus to which it may be exposed. We have developed most 

 valuable qualities at the expense of hardihood, and we must take 

 the consequence. The argument is not that we should part with 

 acquired powers which give the animal its high value, but that 

 we should recognize the attendant dangers and rigorousl}' ex- 

 clude the tubercle germ. 



e. Breeding too Voting. 



Breeding of immature animals is a most fruitful accessory cause 

 of tuberculosis as the demands made upon the system for further 

 growth, for the nourishment of the unborn offspring, and later for 

 the nursing of the calf, or for the dairy yield, undermine the 

 strength and vigor. In different families of that marvelous dairy 

 cow, the Jersey, this has been carried to .such an extent that dis- 

 credit has been thrown upon the whole breed as one especially 

 prone to tuberculosis. 



f. Inbreeding . High-breeding . 



Inbred families of cattle are proverbially subject to tubercu- 

 losis. This is due partly to a resulting constitutional weakness, 

 which often shows itself in an increasing indisposition to breed to 

 near relativ^es, though still fertile with strangers. More frequent- 



