VETERINAKY MEDICINE. 985 



obtained from a great variety of soiuvos, tlie boviiio and Imman tubercle bacilli 

 on artificial nutiieut media possess in common the characteristics of mammalian 

 tubercle bacilli. Slisjbt differences which sometimes appear are not constant or 

 stable. The cultures of bovine and human tubercle bacilli kept under identical 

 conditions grow in the same way. " There is, therefore, an essential unity not 

 only in the nature of tlie morbid ])rocesses induced by human and Itovine 

 tubercle bacilli but also in the ltact«>ri()logical characters of the tubercle bacilli 

 which causes theso processes." 



Veterinary aspect of the tuberculosis problem, J. Pembertiiy {Jour. Roy. 

 Iii><t. Pub. Health, 15 iJ907), Xo. 10, pp. 577-507).— A statement is given of the 

 opinions which are at present held regarding the extent to whicli tuberculdsis 

 in man is due to the same disease in cattle. The author believes tliat it may 

 be very important to discover under what conditions the transmission of tuber- 

 culosis from animals to man takes place. There are many other problems at 

 present but partly understood regarding the transmission of the disease. No 

 amount of uncertainty or lack of information on these points, however, can in 

 any way affect the desirability of preventing in so far as jiossible the use of 

 milk which may contain tubercle bacilli. 



The relative importance of the respiratory and digestive tracts in tuber- 

 culous infection, li. Pfeiffer and E. Friedberger {Dent. Med. Wchnschr., 33 

 {/t)07}. No. 39, pp. 1577-1581). — The authors sought by means of experiments 

 on guinea pigs to determine whether infection with tuberculosis takes place 

 more easily through respiratory organs or the alimentary tract. The results of 

 these experiments indicate that in the case of guinea pigs the inhalation of 1;he 

 minutest quantities of tuljercle bacilli is a much more certain means of bring- 

 ing about infection with tuberculosis than feeding tubercle bacilli. It was 

 necessary to use several thousand times as much to produce infection in the 

 alimentary tract as when infection was brought about in the lungs. 



The susceptibility of tubercle bacilli to modification, J. R. Mohler and 

 11. J. Washburn {U. S. Dept. Agr., Bur. Aiiiin. Iiulu>i. Upt. 1906, pp. 113-163. 

 pis. 'i). — The literature relating to the modifications which tubercle bacilli 

 may undergo is critically reviewed in connection with a bibliograithy. Upon 

 the basis of experimental work the authors come to the conclusion that in some 

 instances tubercle bacilli may be modified not only in form but in pathogen- 

 icity and in cultural characteristics. Virulent cultures may be attenuated by 

 continued artificial cultivation. The virulence of cultures may also be in- 

 creased b.v repeated passage through dogs or other experimental animals. In 

 this way avian tubercle bacilli were brought to a high degree of virulence. 



The cultural characteristics of tubercle bacilli change with the pathogenicity 

 of any particular culture. As the bacilli becomes attenuated they grow more 

 abundantly upon artificial nutrient media. When grown artificially tubercle 

 bacilli may be promptly altered with almost every change of the nutrient 

 medium to which they are transferred. The morphology of the bacilli is, there- 

 fore, so unstable that little dependence can be placed on the mere finding of 

 certain forms of tubercle bacilli in a given case of tuberculosis. 



Tubercle bacilli in butter: Their occurrence, vitality, and significance, 

 E. C. SciiROEDEH and W. E. Cotton {U. S. Dept. Agr., Bur. Aniin. Indus. Circ. 

 127, pp. 23). — In milk, tubercle bacilli are carried upward with the cream and 

 downward with the sediment. They, therefore, occur in greater i)roportion in 

 the cream and ultimately in the butter than in the whole milk from which the 

 liutter was made. Tubercle bacilli may remain virulent in salted butter for a 

 long time, even after 9!) days showing only a slight reduction of their virulence. 

 There is nothing In butter except suit to act us an antiseptic and its action in 



