204 
AERIAL CONTAMINATION AS A FALLACY IN THE 
STUDY OF AMOEBIC INFECTIONS BY CULTURAL 
METHODS. 
A PRELIMINARY NOTE. 
By R. T. WELLS, M.A., M.B., Capt. I.M.S. 
With Plate VI. 
CONTENTS. 
PAGE 
I. Introduction ......... 201 
II. Technique .......... 207 
III. Morphology and life cycle of the amoebae . . . 209 
IV. Conclusions.217 
References ......... 218 
Explanation of Figures ....... 219 
7. Introduction. 
Dysentery is usutilly classified as (i) bacillary, and (ii) amoebic. 
In 1898 Shiga described a bacillus {B. dysenteHae, also kuown as 
Shiga’s bacillus), as the cause of epidemic dysentery in Japan. Since 
then his observations have been, in the main, confirmed. Other 
varieties of dysentery bacilli have been described and “ Bacillary 
Dysentery ” seems now to be a well-defined disease capable of study 
by ordinary bacteriological methods. 
With regard to amoebic dysentery, on the other hand, much 
confusion and radical difference of opinion still exists. Indeed the 
causal role of amoebae in so-called amoebic dysentery does not seem 
to be finally established (Strong, 1907 ; Tanaka, 1910). 
A form of dysentery associated with the presence of motile amoebae 
in the stools had long been recognised, but the work of Schaudinn 
(1903) first gave definition to the subject and indicated lines of re¬ 
search which have since been followed by several other observers. He 
