106 
find that Dr. Houston examined for the Commission over 
oe. 
one thousand oysters, from “ some of the purest waters,”’ 
and from others “ obviously lable to pollution,” with the 
result that nearly all the oysters, ‘from whatever laying 
they were taken, contained Bacillus coli communis, or other 
B. coli closely allied to it.” Dr. Houston found, however, 
a very much smaller number of these organisms in the 
oysters stored in pure waters than in those from polluted 
waters. Consequently the Commissioners state that they 
should not be justified in recommending that the closing 
of a bed or laying should depend as a matter of routine on 
the results of a bacteriological examination—which is very 
much the conclusion at which we had arrived, and the view 
that I gave in my evidence. 
In taking samples of suspected shell-fish I would 
attach great importance to personal supervision by a 
scientific or fisheries expert. The samples should obviously 
not be taken by the parties interested, and they should not 
be taken by disinterested, but untrained collectors who 
may miss seeing some qualifying factor or some important 
piece of evidence. A knowledge of the local conditions, of 
the influence of tidal and other currents, and of prevalent 
winds, may be of great value in judging of the presence and 
extent of pollution, and of the parts hable to be affected at 
a particular time of day or month. Consequently a 
personal examination of the locality by a scientific man 
is always important. Samples from various parts of the 
same bed may have to be taken at different states of the 
tide, and these should be chosen with knowledge and 
discrimination. 
Any additional evidence that can be obtained from an 
inspection of the physical and biological conditions on 
the bed is all the more important because of our want of 
exact knowledge as to the meaning and yalue of some 
