The Intraperitoneal Lysis of Tubercle Bacilli. 67 



the organisms themselves. The race that I worked with in 1901 

 was a conjugating race which died out in the 742d generation. 

 Woodruff's long line of over 3,500 generations is a non-conjugating 

 race and the two races cannot be compared in regard to vitality, 

 since normal conjugation was prevented in the conjugating race, 

 whereas in the non-conjugating race there has been no artificial 

 prevention of a normal process. The following conclusions may 

 be drawn; they must be considered provisional, however, since the 

 experiments are not yet concluded. 



1. The traditional view that each Paramecium is a potential 

 germ cell is not true. 



2. Some descendants of an ex-con jugant are potential germ 

 cells, others are not. 



3. The life history of conjugating lines has shown that if 

 conjugation is prevented, the race dies out. 



4. Weismann's hypothesis that natural death is absent in 

 protozoa is not borne out by the facts. 



5. Care must be exercised in arguing that one effect of con- 

 jugation is to bring about variations because of amphimixis until 

 we know that such variations are not brought about by every 

 individual ex-conjugant in its normal development. 



47 (743) 



Note on the intraperitoneal lysis of tubercle bacilli. 



By Wilfred H. Manwaring and J. Bronfenbrenner. 



[From the Laboratories of the Rockefeller Institute for Medical Re- 

 search, New York.] 



In a previous communication, 1 it was shown that tuberculous 

 guinea-pigs, rabbits and dogs react to intraperitoneal reinoculation 

 with tubercle bacilli by causing rapid degenerative changes in 

 the injected bacteria and a rapid decrease in their number, not 

 observed in normal animals. The question now arose as to the 

 mechanism of this heightened peritoneal resistance. From the 

 similarity between this phenomenon and the Pfeiffer reaction 



1 These Transactions, 191 2, X, p. 30. 



