446 BIOLOGY OF PNEUMOCOCCUS 



the animals to withstand infection is due to transmitted constitu- 

 tional factors unrelated to those which account for the specific 

 immune state. The report of Eguchi (1925) 351 is one of the few 

 communications dealing with this phase of immunity. The young 

 of female mice which, during the period of gestation and lacta- 

 tion, had received repeated intravenous injections of killed Type 

 I pneumococci were found to be immune to organisms of the same 

 type as those employed for immunizing the mother. The ability of 

 the mother to protect the offspring disappeared between the six- 

 teenth and twenty-eighth day after the last immunizing injection. 

 Eguchi believed that protection was conferred through the milk of 

 the immune mother. The results of attempts to transmit specific 

 immunity to the progeny by similarly treating the male parent 

 were inconclusive. 



Another natural medium for the transference of specific immune 

 bodies is the serum of patients convalescent from pneumococcal in- 

 fection. Gundel (1931) 565 studied the curative action of conva- 

 lescent serum and while it was found to be inferior to the usual 

 therapeutic serums of animal origin, yet, according to Gundel, 

 specific therapy with human serum possesses advantages over the 

 use of animal serum in the avoidance of anaphylaxis and serum 

 disease. Other phases of passive immunity will be described in those 

 sections of the text where a discussion of the mechanism is espe- 

 cially pertinent to the particular subject under consideration. 



Allergy and Anaphylaxis 



In addition to rendering a susceptible animal immune to infec- 

 tion by Pneumococcus, the intact pneumococcal cell and its sepa- 

 rate or conjugated components possess the capacity to alter the 

 reactivity of the body tissues to derivatives of the coccus when 

 parenterally introduced. Animals so sensitized may develop acute 

 fatal anaphylactic shock when appropriately injected with cer- 

 tain of the derivatives of Pneumococcus, while the uterus and the 



