112 SIGNIFICANCE OF LEUCOCYTOSIS 



are not too profoundly injured thereby to perform their functions 

 of self -nutrition in a normal manner. 



The question whether we can narrow down the issue to one 

 particular set of cells which always occur in the connective and 

 other tissues to wit, the leucocytes is a more difficult one. We 

 have already adverted to the researches of Romer, who found that 

 antiabrin was present in immunized animals in greatest amount 

 in the organs that are rich in leucocytes, and Metchnikoff has 

 brought forward a whole series of researches which point strongly 

 in the same direction. The discussion of some of these will be 

 deferred to a subsequent chapter, since they hardly seem to 

 indicate that the leucocytes form antitoxin, though they do go 

 to prove that they discharge another and equally important 

 function in the production of immunity to toxins. Here it will 

 only be necessary to point out some well-known and important 

 facts which appear to have a bearing on the question of the 

 origin of antitoxin. We allude especially to the chemotactic 

 attraction for leucocytes which is shown by almost all toxins 

 when not present in too great an amount. In virtue of this 

 attraction the most marked and constant feature of intoxication 

 is the presence of an excess of leucocytes, and this is, in general, 

 most marked when there is a balanced contest between the toxin 

 and the host i.e., when the latter is neither destroyed at once 

 nor shows but little effect of the injection. It is practically a 

 general rule that wherever the host is victorious in the struggle 

 with the toxin there is an excess of leucocytes ; and even where 

 the fatal issue is not averted there is some leucocytosis, unless 

 the intoxication is a very grave one and very rapidly fatal. This 

 is well known in human pathology in the infective processes, 

 where a diminution of the number of leucocytes is a bad sign, 

 whereas hyperleucocytosis is a good sign in so far as it indicates 

 that the infection, though intense, is being combated by the 

 patient by the best means at his disposal. Many researches have 

 indicated that the same law holds in these intoxications. Thus 

 Chatenay, in an exhaustive study on the reactions of the more 

 important toxins, finds that a dose that is rapidly fatal brings 

 about a fall in the leucocytes, whereas smaller doses cause hyper- 

 leucocytosis ; thus, in the guinea-pig about 100 lethal doses are 

 required to prevent the occurrence of the latter. Now we 

 can scarcely imagine that so widespread and constant a phe- 

 nomenon is without some meaning or without some use to the 



