584 INFECTION AND IMMUNITY. 



cultures: In bouillon which contains 5 per cent, 

 of glycerin and which is 2 per cent, acid to phenol- 

 phthalein the bovine bacillus produces a neutral 

 or faintly alkaline reaction in from three to sev- 

 eral weeks, whereas the human bacillus, after caus- 

 ing temporary alkalinity, produces a terminal 

 acidity of from 0.5 to 1.5 per cent. On the basis 

 of this test and other points the bacilli of two cases 

 of mesenteric tuberculosis in man were recognized 

 as bovine in type. In view of the fact that infec- 

 tion of man with the bovine bacillus has been 

 shown to be possible, we are justified in con- 

 sidering the meat and especially the milk of tuber- 

 culous cattle as the probable sources of infection 

 in a limited number of cases. 

 congenital Comparatively few cases of undoubted congeni- 



Tnberculosis. J 



tal tuberculosis have been observed, and in such 

 cases the mothers are usually in an advanced stage 

 of the disease. It is probable that the organisms 

 reach the fetus following metastatic invasion of the 

 placenta. In a number of cases in which the 

 mother had advanced tuberculosis the organs and 

 blood of the fetus (stillborn or dying soon after 

 birth), contained very many bacilli, although his- 

 tologic lesions had not as yet been produced 

 Warthin and Cowie suggest that the tissues of the 

 fetus may possess considerable immunity in such 

 cases. Baumgarten is a strong believer in the pos- 

 sibility that tubercle bacilli may pass to the fetus 

 during pregnancy and, remaining latent in some 

 of the tissues (lymph glands) for a long period, 

 cause active tuberculosis later in life. Others who 

 are less radical still admit that we should consider 

 this as a possibility (Warthin and Cowie, Har- 



