1 66 WOOLFOLK : 



Nichols, Descos and Ravenel proved by feeding health}^ 

 dogs on tuberculous fluids and examining the chyle in the 

 thoracic duct a few hours later that tubercle l)acilli may 

 readily pass through the intestinal wall and infect the animal 

 without causing lesions in the intestines. 



The reason the bacilli more often lodge in the lungs and 

 aflfect those organs than any other part is simply because of 

 the bacilli being brought there b}' the circulation of the lymph- 

 atic and blood sj'stems, all of which is strained through these 

 minute capillaries, and also because of the infection brought 

 about by the inspired air. Nowhere else in the body does so 

 minute a sieve and natural field exist for aerobic bacteria as 

 in the lungs, and the}' may be called the natural habitat of 

 the tubercle bacilli, for it is here they flourish most easily and 

 rapidl}^ 



The theoiy or supposition that the lungs of persons are 

 viost frequently affected by sputum which has become dried 

 and pulverized after being expectorated by persons affected 

 with tuberculosis, is generally becoming accepted as erroneous 

 — first, because sputum does not pulverize easih' and loses its 

 infectious character in a short time, and secondly, because 

 the frequency of infection of the lung is accounted for, as I 

 have just stated, by way of the digestive tract through the 

 taking in of food and drink contaminated with the tubercle 

 producing micro-organisms. 



As a corallai'v to what I have attempted to bring before 

 you in regard to animal tuberculosis and the exceeding proba- 

 bility of its being transmitted to man through meat and milk, 

 and its manner of transmission, I will now give you a few 

 ideas of what we are doing in way of practical meat inspec- 

 tion — what we look for, how we conduct it, and what it 

 means to the public health. 



Federal meat inspection laws governing the interstate 

 and export transportation of meats and animals intended for 

 food have been in existence for a number of 3'ears, but not 

 until about 1891 was any great effort made to have inspection 



