4) 
watched and compared with that of similar oysters left on 
the bed at Bangor. 
I think it is a question whether the spat on the Ogwen 
bed is derived wholly from the old oysters in sight, or 
whether its source may not be individuals in deeper water 
somewhere in the neighbourhood. I propose to visit the 
bed myself during next spawning season in order to try 
to settle this and several other questions in connection 
with the reproduction and spatting of the oyster. 
The further point has been raised that the Ogwen River 
oyster-bed may be liable to sewage contamination from 
the drains of Bangor. The observations made by Mr. 
Scott and the samples brought back by him, although not 
absolutely conclusive on this poimt, certainly suggest 
material of sewage origin, and it is difficult to believe that 
under certain conditions of wind and tide the bed can 
escape from pollution by the town drainage. However, 
this is a matter that may require further investigation, 
and in any case it does not affect the value of the locality 
for the production of spat and the rearing of young 
oysters which may be fattened elsewhere before being 
placed on the market. The whole question of the dis- 
posal of sewage and the pollution of our rivers, estuaries 
and sea shores is one that is in an unsatisfactory condi- 
tion, and requires more careful consideration than it has 
yet received. 
I desire to draw the attention of the Committee to some 
points In connection with the so-called * Bacterial treat- 
ment” of sewage (by coke filter beds or by septic tanks), 
which is now being adopted in various parts of the 
country. The recently published report to the London 
County Council by Professor Clowes and Dr. Houston 
shows that the effluent discharged after such treatment, 
although it may seem pure and have some objectionable 
