BACTERIAL INVASION 215 



tracts will be referred to below as Mi and M2 re- 

 spectively. Lastly, the muscular coat of the intestines 

 was ground in a meat chopper and extracted with four 

 volumes of saline for a few hours and then centrif uged 

 to remove insoluble material. This extract of the 

 muscle coat will be designated as C, 



The B. coli obtained from the intestinal lumen was 

 grown in broth culture for 24 hours ; 10 cc. of the cul- 

 ture was mixed with 0.2 cc. of extract S and incubated 

 for 30 minutes ; then 0.1 cc. of Mi was added, and incu- 

 bation continued for another 20 minutes. 



One tenth of a cubic centimeter of this mixture was 

 injected into the marginal vein of a rabbit's ear, where- 

 upon the animal developed symptoms identical with 

 those of anaphylactic shock and died in three minutes. 

 Injection of a similar preparation containing M2 in 

 place of Ml led to the same end, although the onset of 

 the anaphylactic reaction was considerably delayed. 

 Similar injection of an equivalent quantity of the coli 

 culture without the addition of the intestinal extracts 

 did not cause the appearance of shock or death. In- 

 jection of a mixture of S and Mi or M2 in quantity 

 equivalent to that employed in the first experiment led 

 to a mild shock but death did not follow. Injection 

 of a like quantity of a mixture of 10 cc. of the extract 

 of the muscular coat (C) and 0.2 cc. of S caused 

 anaphylaxis and death, although the onset of symp- 

 toms was not so rapid as in the experiments with the 

 mixtures containing B. coli. 



Essentially the same findings were obtained in the 

 case of dogs, provided the amount of the injected ma- 

 terial was increased proportionately to the difference 

 in weight of these animals. 



