A. Balfour 
123 
generation of spirochaetes was evolved. He did not, however, show how 
such evolution occurred. Moreover in my later work, which apparently 
Hindle has not seen, for the last of my papers which he quotes is one 
that appeared in April 1911, I clearly expressed my belief that these 
granules are of an infective nature and are intimately concerned with 
the life-cycle of the spirochaete. I see that, like myself, Hindle has not 
derived vei-y much information from preparations stained by the more 
ordinary methods. I trust, however, that he will find the process of 
vital staining of great service. I have recently sent a communication 
on this subject to the British Medical Journal. Undoubtedly the most 
interesting portion of Hindle’s paper is that dealing with the life-cycle in 
the tick, Argas persicus. Here again it would seem that he has not had 
his attention drawn to my later work on this subject, especially to the 
paper which I read last July, before the tropical medicine section of the 
British Medical Association when I partly traced the very development 
Hindle has now fully outlined and when I exhibited specimens of tick 
tissues showing the changes from granule or coccoid body to bacillary 
and spirochaetal forms. This paper was published in the Journal of 
Tropical Medicine and Hygiene for September 1st, 1911, and later in 
the Bi'itish Medical Journal for November 11th, 1911. A much earlier 
paper (Oct. 1st, 1909) in the former journal has also apparently been 
overlooked. It signalises the discovery of granules in the tick and 
records successful inoculation experiments with them. 
The subject is further partly dealt with and very fully illustrated in 
the Fourth Report of these laboratories. Volume A which appeared in 
November 1911. The experiments there detailed were mostly carried 
out early in that year. I have no wish to dispute the question of 
priority in this portion of the research, for Hindle and I would seem 
latterly to have been working at the subject more or less contempora¬ 
neously and, in any case, it was Leishman who led the way. It is only 
fair, however, to direct attention to papers which are the outcome of 
several years of a research that had to be sandwiched in between 
administrative and routine work whenever time permitted. I see that 
Hindle has outstripped me for he has carefully worked out the complete 
cycle which I have not had time to do. There are, however, apparently 
differences between the development of his strains and that with which 
I have been working, for whereas he finds that the spirochaetes them¬ 
selves penetrate the cells in the tick and there break up into coccoid 
bodies it would seem that in the case of the Sudan fowl spirochaete 
only the granules do so. It is this, along with certain other features. 
