MICROSCOPIC ORGANISMS IN INTESTINAL CANAL, 247 
bacteria in the excreta, it may be noted that the results of the 
present series of observations are entirely opposed, in certain 
respects, to those at which Nigeli appears to have arrived in 
Enrope. In his work ‘ Die niederen Pilze in ihre Beziehungen 
zu den Infections-krankheiten und der Gesundheitspflege,’ he 
affirms that, although bacterial elements are constantly present in 
very large numbers within the digestive canal, they are invariably 
inactive, and on this view he accounts for the absence of ill 
effects coincident with a constant source of infection of the 
system at large, by what he regards as pathogenic agents. He 
affirms that it is inconceivable that bacteria should enter the 
system from the digestive canal—“ weil sie ndmlich im Magen 
und im Darmkanal zuerst durch die freien Stiuren dann durch die 
Salze der Galle geschwicht und bewegungsunfihig gemacht sind. 
This statement can, I believe, only be founded on general prin- 
ciples, and not on actual observations, unless, indeed, the latter 
give very different results in Hurope from what they do in India. 
In India there can be no doubt thatthe lower portion of the 
intestinal canal very frequently, indeed, normally, contains very 
large numbers of active bacteria. After becoming acquainted 
with this very sweeping statement of Nageli’s I made an ex- 
tended series of special observations on this point. The 
results arrived at were as follows:—A very large proportion 
of the alvine excretal matter, on its escape from the body, is 
composed of immense accumulations of bacteria. In very 
many cases these are in active motion, and in others begin to 
move at once, whenever a suitable fluid is employed to dilute the 
basis. Movement is not confined to cases in which the reaction 
of the basis is alkaline or neutral ; it very frequently is present 
coincidently with distinct acidity. Fluidity of the materials 
naturally favours the movement, but the capacity for active 
movement is in very many cases merely concealed, and not 
absent when the basis is much concentrated, as is clearly 
shown by its immediate occurrence on dilution. Depression 
of temperature of the basis causes temporary cessation of activity, 
as demonstrated by experiments conducted when the air tempera- 
ture was comparatively low, in which repeated disappearance and 
reappearance of movement occurred coincidently with depression 
of the temperature of the material below that of the body and 
its subsequent elevation to it, the movements referred to being 
not, of course, mere molecular movements, which might be 
ascribed to movements established in the fluid, but active darting 
progressive ones. The addition of water to the basis at once 
causes an abolition of movement. 
It must, I believe, be due to the effects of depression of tem- 
perature and employment of unsuitable media for dilution that 
