218 THE ACTION OF THE LIVING CELL 



however, B. coli and the mucosal extract together 

 form a highly toxic combination, we must admit that 

 a definite potentiation of some sort is brought about by 

 the mere mixing together of these components. Ap- 

 parently the presence of the microorganisms increases 

 markedly the toxicity of the cytost initially derived 

 from the mucosa. 



That this is true is indicated by the fact that in the 

 more concentrated dilutions of the extract of the 

 serum taken from the mesenteric vein a toxic action 

 was observed when it was used in conjunction with 

 B. coli, whereas the serum from the femoral vein ex- 

 hibited no such toxicity. This result indicates that 

 the blood leaving the intestine contains a toxic moiety, 

 presumably cytost, which is either excreted or altered 

 in some fashion before it reaches the general circu- 

 lation. 



That the actual toxic agent in these experiments is 

 cytost is evidenced from the fact that immediate au- 

 topsy of the rabbits which died a few minutes fol- 

 lowing the injection of the various toxic mixtures 

 disclosed an acute venous dilation of the splanchnic 

 vessels. Presumably, as in other cases of shock, this was 

 the cause of the sudden collapse and death. 



Just why the presence of the colon organism should 

 so markedly intensify the action of the cytost is not 

 entirely clear, although it seems highly probable that 

 such intensification is due to a surface adsorption of 

 the cytost by the microorganisms. As is well known, 

 colloid particles are in general stabilized by an ad- 

 sorbed ionic layer and the mutual precipitation of 

 oppositely charged colloids involves the interaction 

 of such surface layers. Since, as pointed out elsewhere 



