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Mas produced, with progressive loss of flesh till the weight was reduced 

 hy one-third, death occurring at the end of five or six weeks, when no longer 

 under surveillance. The one inoculated subcutaneously was more severely 

 affected than the other. 



These two inoculations convinced me that, like other well-studied 

 micrococci (e. g., the staphylococcus pyogenes), the tetracoccus is specially 

 pathogenic for young rabbits, and much less for fullgrown ones. Hence in 

 my other inoculations I only used rabbits between 500-1000 grammes 

 weight, males, of the ordinary race of this country, recently brought into 

 town, and either white or black, like the two first in the series. I also 

 suppressed the preliminary filtration, in view of the unreliability of this 

 operation for excluding live genus. 



I shall not weary you with a detailed account of all the twelve young 

 rabbits inoculated with the "Tetragenus ex mosquito", the clinical results 

 of their observation being given in the accompanying Chart, under the 

 Letters A and L. These rabbits were inoculated with successive generations 

 of the germs originally obtained from the mosquito which on January 17 

 had stung the yeljow fever patient at the Military Hospital, although in 

 rabbits D, E, P, G, H the tetracoccus injected had passed though rabbits 

 C, D, or E, having been recovered from these with blood collected from the 

 live animals' ears, or from the right auricle of the heart after death. I 

 inoculated cultures of different ages and in variable doses, in order to 

 appreciate how those conditions might modify the ensuing pathogenic 

 effects. 



My two first rabbits appear in the Chart with letters A and B ; their 

 weights were only noted at the beginning and end; all the others were 

 weighed each day shortly before feeding time, in order to obtain their 

 minimum daily weight. The usefulness of the weight tracings for the fuller 

 comprehension of the clinical history is best shown in the case of rabbit C ; 

 its weigth was not affected during the first fortnight, but from this date 

 forward the loss of flesh progressively increased until it reached one-fourth 

 of its primitive weight, this loss coinciding with the acute seven day's 

 fever, similar to that of A and B, which preceded its death. The first fifteen 

 days that followed the inoculation must therefore be considered as a true 

 incubation. This is the only one that has presented such a prolonged 

 incubation, perhaps in some measure due to the circumstance that the 

 tetracoccus had in this case been developed in broth to which 1 per cent, 

 of cane sugar had been added ; for there was also sugar in the old cultures 

 injected into rabbits I, K, L, whose tracing suggests the occurrence of an 

 incubation period of two or three days. 



Cultures made from blood of the ear during the sickness of rabbits 

 C, D, and E all gave the tetracoccus versatilis, either pure or contaminated, 

 the disinfection of the skin having been insufficient. The microbe was, 

 however, carefully isolated before being inoculated into D, E, and F. 



