86 Sl'lKOCUJGTOSIS OK SUDANESE FOWLS 



to obtain, if possible, some information on this ))oint the following; expoiinieiit was 

 carried out : — 



Jiinnnrii "24, X911. 5 v.M. of liluud drawn with aseptic precautions liy a syriu^e from tlie winjj vein of a 

 fowl showing many si>irocha!tes in its bluod. Citrate solution added and the mixture filtered through a 

 small Histeur-Chamberlain filter F. 



Itesulting filtrate found clear of parasites and 10 minims of it inoculated subeutaucously into a clean, 

 healthy chick. The result was entirely negative. It is worth noting here that, at a later date, this chick 

 was sucivssfiilly inoculated with sjiirochiotosis. 



Other points rehiting to the bodies and tlieir eoiuieetion with the spirochiete infection 



are so intimately mixed up with the second of our statements that we may at once proceed 



to its consideration. As space is limited and as records of cases form uninteresting reading 



it is not proposed to give details of all the experiments carried out (some 70 in number on 



chicks alone and many more on fowls, obtained both in the open market and from our own 



specially bred stock), but merely to supply good illustrations as proofs of conclusions stated. 



DifTeienccs of (2) lieference has already been made {page 11) to the fact that there were marked 



ihedisi-aicm differences between the disease in chicks and that in fowls. The most imiwrtant are here 



chicks and ^ 



fowls given in detail, but it must be remembered that to draw definite conclusions from 



experimental work of this kind requires great care, for, as Levaditi and others have shown, 

 it may be impossible, by ordinary methods, to demonstrate the presence of free spirochastes 

 in the blood of a bird, even though, as shown by inoculation, they actually do exist. 

 At the time most of these experiments were conducted, the use of ricin for facilitating 

 the search, as afterwards advocated by Levaditi and Stanesco,' had not been demonstrated 

 and one had to rely on tlic prolonged search of films which, though imiuirtant, was very 

 tiring and occupied a great deal of time. For example, if one inoculated a chick with 

 spirocha;tal blood, and bodies only appeared, and then one inoculated this chick's blood into 

 another bird with the result that spirochtctes occurred in the latter, one could never be 

 absolutely certain that there had not been a few spirochiEtes lurking in the peripheral blood 

 of the first chick, for it would be impossible to examine as a routine the number of films 

 which would represent even the few drops of blood used for an inoculation. Again, it is 

 sometimes very dilficidt to say whether a bird is absolutely clean or harbours a few bodies. 



Bearing these difficulties in mind, tlio following is the list of the differences to which 

 allusion has been made: - 



[a) In chicks, not infrequently, the inoculation of blood containing, so far as could be 

 told, free spirochuBtcs only (and these in large numbers) into a clean chick has resulted, 

 not in the appearance of free spirochtetes, but of what one regards as the intra-corpuscidar 

 stage in that chick's peripheral blood. At a later date, free spirochtetes may also appear. 

 The same phenomena may also follow tick-bite or tlie inoculation of enuilsions of the 

 tissues of infected ticks. Hence it would seem that the term " after phase " may, in 

 some respects, be a misnomer. On the other hand, the inoculation of blood, containing 

 apparently only the intra-corpuscular bodies, has now and again resulted in the 

 appearance of free spirochiEtes at first, and of bodies later. Granting that no spirochajtes 

 had been present in the blood used for inoculation, are we to conclude that the spirochajtos 

 have been derived from the bodies direct or from infective granules (spores or merozoites) 

 into which the bodies have luokin up? Again, supposing that a few spirochiEtes were 

 present but had boon missed, are we to assmne that the blood of the inoculated chick was in 

 a condition favouring cell parasitism which consequently occurred, the spirochiEtes, as 

 granules, at once invading the red cells and appearing as the familiar inclusions'? 



' Levaditi, C, and Stanest;o, V. (lilln). "Sur nn |)rocedc facililant la recherche des tryjutDosomes 

 ct des lilaires dans le sang." C'oinpl. rend dc la &te. dc Biol,, T. Ixvii, pp. 594-596. 



