townsend: asexual stages of verruga organism 665 



plicable, have proved stumbling-blocks, however, in interpreting 

 the asexual development of the organism. It has been repeatedly 

 demonstrated that blood containing the Bartonella gametes in the 

 erythrocytes fails to originate any symptoms upon injection into 

 healthy animals; that the gametes disappear from the erythro- 

 cytes upon the advent of the eruption ; that eruption-tissue inocu- 

 lations produce localized lesions in new tissues without Barto- 

 nella gametes in the erythrocytes; and that such lesions may be 

 produced successively in series of animals by such inoculations. 

 These and related facts are what induced Strong et al. to con- 

 sider the fever and eruptive stages of verruga as two distinct 

 pathologic entities.^ But their finding in ''Oroya fever" cases 

 of the schizonts and merozoites, already shown to be characteris- 

 tic of the eruption tissues, appears to bind inseparably their 

 ''Oroya fever" and "verruga peruviana" as phases of one dis- 

 'ease. The explanation of the several facts above mentioned will 

 appear below. 



It is apparent that the great majority of the Bartonella sporo- 

 zoites introduced by the Phlebotomus within the skin of suscept- 

 ible subjects immediately imbed themselves in the cytoplasm 

 of the vascular endothelial cells at point of inoculation, becom- 

 ing schizonts, which upon maturing break up into merozoites, 

 these elongating within the unruptured host-cell wall and pene- 

 trating such erthrocytes as come in actual and direct contact 

 with the infected cell, whereupon they become immature gametes. 

 The fully formed rods and ovals in the erythrocytes are respec- 

 tively the mature male and female gametes, which can con- 

 jugate only in the Phlebotomus. Hence their injection into a 

 healthy warm-blooded animal fails to originate any symptoms of 

 the disease. There appears to be no duplication or repetition of 

 any of the stages, except that the male gametes increase by 

 binary transverse division. ' 



The endothelial cells of the capillaries of the subcutaneous tissues 

 are evidently the chief seat of the above-described schizogonic cycle 

 of the Bartonella, and here is where the erythrocytes become infected. 



« Ibid., 6, 14, et seq. 



