ESSAYS ON BACTERIOLOGY. 35 



First. It seems to have been shown by Ernst and 

 others that the bacilli may be present and living in the 

 milk of cows whose udders are not tuberculous. The 

 importance of this fact will at once be recognized. 



Second. A series of experiments has been carried 

 out to decide whether the bacilli could penetrate the 

 apparently healthy mucous membrane. The result is 

 the conclusion that they can, together with the discov- 

 ery that they are, under such circumstances, likely to> 

 be caught in the nearest lymph glands, and may pro- 

 duce the phenomena of ordinary tuberculous adenitis. 

 These investigations are held to throw light upon the 

 character of so-called scrofula. 



Third. The immensely important question of la- 

 tent tiiberculosis appears to be nearing a solution, in- 

 asmuch as it has been shown that the bronchial and 

 other glands of apparently healthy persons may con- 

 tain living tubercle bacilli, and this, too, in the ab- 

 sence of any visible tuberculous lesions. H. P. 

 Loomis has recently recorded a series of autopsies, con- 

 firming this statement. If it be shown that long la-' 

 tent tuberculosis may exist in the body, or that bacilli 

 may remain in the body through long periods without 

 producing the disease, it will at once be seen how this 

 fact will explain many things in the clinical history of 

 the disease, and how it may throw light on the still 

 vexed question of hereditary transmission. As to the 

 hereditary transmission of tuberculosis, the investiga- 

 tions are still going on, but a certain conclusion has 



