NOTES. 1041 



infection. Very few control serums reacted, and none before infection. Koch's 

 emulsion gave more constant results. Arloing's homogeneous culture was irregular 

 and did not react in correspondence with it. Precipitation tests with nitrates of 

 tubercle bacilli extracts were negative. The opsonins of Wright and Douglas were 

 weaker in the immunized rabbits; possibly because the phagocytosis was so much 

 greater, this substance was being exhausted. 



The histological study, especially of the lungs, indicated an intense intiltration and 

 congestion in the immunized animals following the virulent inoculation. This 

 increased in degree until the tenth or twentieth day, and then gradually subsided, 

 leaving in many animals practically no trace of tubercles or bacilli. Meanwhile the 

 controls began slowly to form isolated tubercles with caseation leading to a chronic 

 tuberculosis. The prominent characteristics noted were the following: The large 

 collection of epithelioid cells actively engaged in phagocytosis, extravasated blood 

 from the dilated capillaries and a pneumonic appearance of the exudate, absence of 

 caseation, rapid disappearance and degeneration of the bacilli (indicated by their poor 

 staining) , and finally, the absorption of all signs of disease. The conclusion is that 

 the specific, acquired immunity rests on enhanced phagocytosis and bactericidal 

 power of the serum due to opsonins or stimulins. 



In the experimental work with rabbits, as summarized by Dr. Trudeau, no lasting 

 immunity was secured. Vaccinated animals resisted the disease for a longer period 

 after the inoculation with virulent cultures than the control animals. It would 

 therefore appear that some degree of immunity was conferred by vaccination, though 

 in no instance was complete immunity secured. Better results were obtained in 

 vaccination with the living attenuated cultures than with dead tubercle bacilli. Dr. 

 Trudeau referred to experiments in vaccinating rabbits with tubercle bacilli from 

 cold-blooded animal's and with attenuated cultures of human origin. No degree of 

 immunity was apparently conferred by the vaccination with the cultures of the bacilli 

 from cold-blooded animals. The cultures of human origin attenuated by growth for 

 20 years were apparently ineffective in securing immunity as compared with unvac- 

 cinated animals. Slightly better results were obtained by vaccination with cultures 

 attenuated by growth for 14 years. Dr. Trudeau considered it pretty well settled 

 that a living bacillus must be used in securing immunity by vaccination, and that for 

 this purpose the virulence of the organism is a matter of much importance. 



In discussing the above papers Dr. Welch called especial attention to the increased 

 tubercle formation in vaccinated rabbits coincident with a certain degree of immunity. 



Dr. L. Pearson reported that in experiments with monkeys no immunity had been 

 secured by vaccination with avian tubercle bacilli. 



A study of the blood in tuberculosis was the subject of a paper by Dr. J. Ullom 

 and Dr. F. A. Craig. 



Dr. D. C. Twichell reported a study of the Viability of the Tubercle Bacillus in 

 Sputum, kept under a variety of conditions. The maximum period during which 

 the bacillus retained its vitality was about 6 months. Darkness and moisture were 

 conditions most favorable to prolonging the duration of the life of the bacillus. 



Several papers were read by title, among which was one on the Stability of Cultu- 

 ral Characteristics among Races of Tubercle Bacilli, by Dr. Theobald Smith. 



Control of Gypsy and Brown-tail Moths in Massachusetts. — An act recently passed by 

 the State legislature of Massachusetts makes provision for the appointment of a super- 

 intendent for suppressing the gypsy and brown-tail moths, and outlines the duties of 

 cities and towns in that connection and the conditions under which they may be 

 reimbursed in part for the expense of suppression. The bill appropriates $300,000, 

 of which $75,000 may be expended during the calendar year 1905, $150,000 during 

 1906, and the remaining $75,000, with any unexpended balances, up to May 1, 1907. 

 An additional sum of $10,000 in each of the 3 years may be expended for experi- 



