6 
Sp i rochaeta icterohaemorrllagiae 
the blood or liver of guinea-pigs inoculated with blood from cases of Weil’s 
Disease. Unfortunately I am not able to say whether they were pathogenic, 
but I think there can be little doubt about this. 
As to the finer morphological characteristics, Noguchi, describing the 
spirochaetes found in the rats in New York, says: 
“The morphology of the organisms corresponds with that of the Japanese 
and Belgian strains with which we compared it.” The Belgian strain was 
received from Dr Adrian Stokes. 
“Its elementary structure is that of a closely wound slender cylindrical 
thread with tapering ends, averaging 9/x by 0*25 \x. The number of coils is 
greater in a given length than that of any spirochaete hitherto known. It 
is so closely wound that within 5 /x there are 10 to 12 coils. Near the extremities 
the coils become closer. They are never very deep, and in general, the aspect 
of the whole body is that of a transversely barred chain of streptococci. The 
winding is rarely seen distinctly, although it can be brought out well by a 
carefully fixed, stained preparation (osmic acid vapour and Giemsa stain) or 
under powerful dark field illumination. It should be noted that the description 
of the organism by most authors leaves this point unclear, and so far no 
satisfactory microphotograph has been reproduced.” 
When I read this description in the earlier part of last year I at once 
re-examined the numerous stained preparations I had of the spirochaetes 
from the blood and liver of inoculated guinea-pigs, but I could not satisfy 
myself that these organisms showed the structure Noguchi had described. 
Some months later when I found these spirochaetes in the kidney of rats, 
I saw the minute spirals in many without any difficulty and subsequently 
found them in some guinea-pig preparations which had not been fixed before 
staining. 
The secret, in my opinion, of a successful preparation is not so much in 
the method of staining as in the absence of fixing. 
If for example two blood films from an inoculated guinea-pig be air-dried, 
and if when thoroughly dry one be fixed in absolute alcohol (10 minutes or 
more), and the other be moistened for a few minutes with distilled water and 
then both be stained in Giemsa’s solution (preferably made with faintly 
alkaline distilled water) for the same time say two, three, or four hours, the 
fixed film will probably not show the minute spirals whilst the unfixed film 
will exhibit them very distinctly at least in parts of the film. 
I have found these spirals in some of the spirochaetes from each of the 
positive cases, and if in doubt about a spirochaete am not satisfied until this 
structure is found in some of them. 
The spirals vary, some are coarse and easily seen, others are finer and 
more closely packed together, but in all cases they become closer and less 
evident towards the extremities of the spirochaete. They are seen with a 
magnification of 800 to 1000 distinctly. 
o t/ 
Noguchi writes: “The part of the body which forms the hook termination 
