SPIKOCHiETOSIS OF SUDANESE FOWLS 101 



There is, I think, no need to multiply the records of cases; "606" in sufficient Results are 

 doses can certainly banish spirochictes from the peripheral blood and in certain instances f*™"'^*'"'^ 

 absolutely cure the bird. In other cases the granule phase supervenes on which the 

 drug has apparently only a limited effect and sometimes, possibly, none at all. This 

 question will be discussed immediately, and the nature and significance of the action of 

 "606" will be found dealt with in that part of the paper termed "The ilechanism of 

 the Crisis " (ride paye 102 j. 



It only remains to be said that chicks are very susceptible to the toxic effects of 

 the drug, and that it is much more easy to cure adult fowls with it than the delicate 

 and immature bird which usually perishes from the combined effects of the infection and 

 the medication. 



2. Effects on Ixtka-cohpusltlak Fokjis 



In one of the earlier experiments, a chick with a heavy "body" infection was given 

 too large a dose of "606" and died a few hours afterwards. Apparently as a result 

 of the administration of the drug, while there was no diminution in the number of 

 bodies found in the heart's blood, they had undergone considerable change, breaking 

 up into " spore " forms, several of which were discharging granules from the red cells. 



These granules were found lying free in clusters (Plate IV., tig. 3)T 



It is perhaps scarcely necessary to give in detail the dozen experiments carried out 

 to discover how "606" affects the inclusions. It may be said at once, that, as was to 

 be expected, there is no rapid action on them as upon the spirochetes. In the majority 

 of cases, however, the drug seems to hasten the disappearance of the bodies. It is, of 

 course, difficult to say in any individual case that the disappearance is due either wholly 

 or in part to the "606" as the condition tends towards cure in many cases. 



Still, when one finds a fowl with a heavy infection treated by the drug and its blood 

 freed permanently from the intra-corpuscular forms in the short space of eight days, 

 the result is suggestive. In some instances, as in the case recorded above, "606" 

 appears to hasten the breaking \i]i of the bodies into "spores" and the discharge of 

 the latter from the red cells. In such cases I have seen the infection increase, possibly 

 because some of the free granules escaped destruction and re-invaded the erythroblasts. 

 There is no doubt that they are much more resistant than the free spirochietes and The granules 

 this fact may yet throw- some light on the persistence of spirochaetal infectious in man. ^"^ "'°''<= 



•' -^ ox- r resistant than 



Death frequently i-esults in the case of fowls in the "after phase," or as one may now free spiro- 

 perhaps call it the " granule phase," when they are treated by the Ehrlich-Hata "^''*'^'' 

 preparation. 



It will be necessary to carry out many more experiments before the precise action 

 of the drug on the inclusions and the infected birds can be ascertained. 



In some of the fatal cases the organs examined by the Levaditi method, and more 

 especially the liver and lung, showed rather suggestive clumps of little black granules 

 which may have resulted from the blood infection, but I am not prepared to be dogmatic 

 as to their origin. On no occasion was any appearance met with resembling the great 

 granule infection presented by the organs of the chick treated for acute spirochaetosis 

 by " 606." 



The Mech.\xism of the Crisis 



As Eevealed by the Dark-Field Method 



I uow pass to some most interesting and suggestive work recently carried out and 

 still uncompleted, which, as already indicated in several places throughout this paper, 



• For Plate IV., fig. 3 read Plate III., fig. 3 



