366 INFECTION AND RESISTANCE 



in smooth muscles under the influence of serum is markedly aug- 

 mented if the preparations are taken from sensitized animals. 



In addition to these predominant features of the anaphylactic 

 symptomatology in guinea pigs, there are a number of secondary re- 

 actions which, though less prominent, are nevertheless of considerable 

 interest and theoretical importance. The conditions in the circula- 

 tion are probably, to a great extent, dependent upon the respiratory 

 condition, and the fall of blood pressure in guinea pigs is regarded by 

 some investigators as merely a secondary manifestation just preceding 

 death. The fall of temperature first described by H. Pfeiffer, 17 

 however, seems to be an occurrence which, though standing in no 

 causative relation to the symptoms as a whole, is so constant and well 

 marked that it has been taken by a number of workers as one of the 

 necessary criteria for the characterization of the anaphylactic con- 

 dition. 



There is, indeed, an almost regular drop of several degrees in the 

 rectal temperature, and a close observation of this may be of much 

 aid in determining the occurrence of mild reactions, when other 

 symptoms of shock are not strongly marked. Pfeiffer 18 himself 

 goes so far as to claim that by this symptom alone delicate anaphy- 

 lactic reactions may be determined when all other symptoms are 

 lacking. 



Friedberger, 19 20 too, has found the sudden drop of temperature 

 a very regular occurrence, and has employed this method of study 

 for the analysis of the intensity of anaphylactic shock. He calls 

 attention to the apparent difference between infection and anaphy- 

 laxis in this respect in that in the former there is fever, in the latter 

 there is depression of body heat ; but, at the same time, he points out 

 that this discrepancy is an apparent one only, and determined by 

 quantitative differences, for when he treated sensitized animals with 

 varying doses of antigen he found that quantities which produced 

 other anaphylactic symptoms of noticeable degree would regularly 

 depress the temperature as Pfeiffer had shown. It was possible, 

 however, to determine a minimal dose necessary for temperature 

 reduction. Quantities just below this left the temperature un- 

 changed, and still smaller quantities produced fever or even in- 

 creased the temperature. This fact is extremely significant in that, 

 as we shall see, it has an important bearing upon views which inter- 

 pret bacterial infection as a series of anaphylactic poisonings, the 

 multiplying bacteria furnishing the constant supply of minute 

 amounts of antigen. This thought, indeed, based also on the study of 



17 H. Pfeiffer. Wien. klin. Woch., No. 1, 1909. 



18 Pfeiffer u. Mita. Zeitschr. f. Immunitdtsforschung, Vol. 4, 1910. 



19 Friedberger. Deutsche med. Woch., No. 11, 1911. 



20 Friedberger und Mita. Zeitschr. f. Immunitdtsforschung, Vol. 10, 1911, 



