ll 
STUDIES UPON HYPERSUSCEPTIBILITY AND IMMUNITY.' 
By Miltox J. Rosenau, 
Passed Assistant Surgeon, Director Hygienic Laboratory, 1. S. Public Health and 
iU ' Marine- Hospital Service, 
and 
JoHX F. Axdersox, 
Passed Assistant Surgeon, Assistant Director Hygienic Laboratory, U. S. Public Llealth 
and Marine- LLospital Service. 
* We have shown* that horse serum is apparenth" a bland and harm- 
* less substance when injected into a normal guinea pig, but this injec- 
tion renders the guinea pig susceptible to a subsequent injection of 
, * horse serum. At least ten days must elapse between the first and the 
i second injection for this hypersusceptibility to manifest itself. 
; The present bulletin gives the results of our further work upon 
this interesting phenomenon. We have endeavored to obtain a deeper 
■ insight into the cause and nature of hypersusceptibility and have 
! attempted to localize the phenomenon in certain fluids, cells, or organs 
! ' of the body. 
,i We foresaw last year that the problem of hypersusceptibility has an 
! important bearing upon the question of immunity and expressed the 
' opinion^ that “resistance to disease ma}" be largely gained through a 
i process of hypersusceptibility. Whether this increased susceptibility 
is an essential element or only one .stage in the process of resistance 
ji to disease, must now engage our attention.” We can not escape the 
« Manuscript submitted for publication April 27, 1907. 
] ^Rosenau, M. J., and Andereon, John F. : A study of the cause of sudden death 
' following the injection of horse serum. Pub. Health and Mar.-Hosp. Serv., Hyg. 
Lab. Bull. Ro. 29, T906. 
; A new toxic action of horse serum. Journ. med. research, Yol. 15, No. 1 
(n. s., Yol. 10, No. 1), July, 1906, pp. 179-208. 
Anderson, John F. ; I. Maternal transmission of immunity to diphtheria toxine. 
II. IMaternal transmission of immunity to diphtheria toxine and hypersusceptibiiity 
' to horse serum in the same animal. Pub. Health and Mar.-Hosp. Serv., Hyg. Lab. 
Bull. No. 30, 1906, and Journ. med. research, Yol. 15, No. 2 (n. s., Yol. 10, No. 2), 
Sept., 1906, pp. 241-260. 
^Rosenau, M. J., and Anderson, John F. : Hypersusceptibiiity. Journ. Am. Med. 
Assn., Yol. 42, No. 13, Sept. 29, 1906, pp. 1007-1010. 
( 7 ) 
