523 
SOME NOTES ON THE MORPHOLOGY 
OF SPIROCHJETA DUTTON I IN THE 
ORGANS OF RATS 
BY 
J. J. van LOG HEM, M.D., Amsterdam 
(PRIVAT DOCENT IN BACTERIOLOGY, THE UNIVERSITY OK AMSTERDAM) 
From the Runcorn Research Laboratories 
( Received for publication , December 3 rd, 1907 ) 
The strain of Spirocheeta duttoni, brought from the Congo by 
Dutton and Todd, is maintained in the Runcorn Research Labora¬ 
tories through inoculation of infected blood from rat to rat. By 
Levaditi’s 1 silver method I have investigated the morphology of the 
parasites in the organs of some of these animals killed at different 
stages of the infection. 
The principle of the silver method may be briefly stated as follows: lhe 
organs, after fixation in formol, are impregnated with a solution of silver nitrate, 
and then exposed to the reducing action of pyrogallic acid. In thin paraffin 
sections the tissues appear of a bright yellow colour, with sufficient differentiation 
of the nuclei ; the spirochaetes black, with sharply defined outlines. To bring out 
the relation of the parasites to the tissues, Giemsa’s or other stain may be 
employed. 
The pyridin-silver modification, the ‘second method’ of Levaditi, gave 
generally good results, not only with fresh material, but also in organs which had 
been kept for some months in formol. 
Details of the course of experimental spirochaete-infection in rats 
may be found in the extended study of Breinl and Kinghorn; 2 here 
it is only necessary to repeat that the maximum number of parasites 
in the peripheral circulation is reached on about the fifth day after 
inoculation, after which the spirochaetes disappear rapidly and 
completely, until the first relapse, which occurs in about a week and 
extends over one to three days. , , 
Examination of sections (4 to 0 n) of the organs o rats, 
at the height of the infection, shows the large and sma 00 
and capillaries crowded with spirochaetes, in accordance wi 
observations of Levaditi. 
