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its significance the following specious argument: if the tetragenus that is 

 found upon the skin of yellow fever patients were the cause of yellow 

 fever, you would expect the disease to be eminently contagious by mere 

 contact for susceptible persons, whereas this is known not to be the case. 

 In this argument, however, two capital points are overlooked : one is that, 

 according to my ideas, the germ of yellow fever is only pathogenous when 

 introduced by inoculation; and the other, that the presence of the tetra- 

 coccus on the skin of the patients should not be considered as the cause, 

 but as the result of the infection, and I plausibly attribute it to an 

 elimination of the microbe by the cutaneous secretions, as happens with 

 the ' staphylococcus aureus," as A. Preto proved in 1892 (Bacmgarten's 

 Jahresbericht, 1892, vol. viii. p. 44.) The fact of finding the tetracoccus in 

 the milk of one of my yellow fever patients certainly confirms this view. 

 On the other hand, it is of no importance that the same micro-organism 

 be found on the skin of acclimated patients, for there is no reason why it 

 should not penetrate into the system and be eliminated with their secretions 

 without occasioning a disease against which those persons are immune ; 

 and it may be further postulated that the tetracocci developed in the tissues 

 of such immune subjects will probably have lost their virulence, or will 

 have it more or less attenuated. Dr. Sternberg's investigations have 

 shown that after death from yellow fever the blood and tissues are 

 found invaded by other bacteria besides the specific germ of the disease. 

 It is very probable, therefore, that such associations, retarding or impeding 

 (as I have witnessed) the growth of the tetracoccus, may account for the 

 only exceptional development of the latter in the cultures from heart 

 blood from liver and kidney juices obtained by Dr. Sternberg, and also 

 once by Dr. Gibier, and by our worthy member Dr. Tamayo. 



I consider, therefore, the presence of the tetracoccus in yellow fever 

 patients as sufficiently proved. 



The second condition, that the tetracoccus should be isolated in pure 

 cultures, offers no difficulty. 



The third condition is the reproduction of the disease in healthy 

 susceptible subjects. This, for obvious reasons, could not be attempted in 

 man with so serious a disease as yellow fever ; nevertheless, I can almost 

 be said to have achieved it in some of my mosquito inoculations, having 

 obtained the tetracoccus from the head and proboscis of the insect after 

 the inoculation, and the inoculated person falling ill with a mild 

 albuminuric yellow fever. To-day bacteriologists are content with proving 

 that the micro-organism is pathogenous for animals, without exacting that 

 the disease be reproduced in them with the same symptoms observed in 

 man. With how much more reason may not I consider that the above 

 condition is fulfilled when in my inoculations of pure tetracoccus cultures 

 into young rabbits I have produced a fever of a special type, presenting, 

 like yellow fever, two paroxysms, death attended with eclampsia, and 



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