462 



SCIENCE. 



[N. S. Vol. II. No. 41. 



I. The beneficial effects of aeration — 

 (a) By the addition of air only; 



(6) By change of water; 

 pointing to the conclusion that the laying 

 down of oysters in localities where there is 

 a good change of water, by tidal current or 

 otherwise, should be beneficial. 



II. The diverse results obtained by feed- 

 ing upon various substances, amongst which 

 the following may be noted. The exceed- 

 ingly harmful action of sugar, which caused 

 the oysters to decrease in weight and die ; 

 whilst the other substances detailed above 

 enabled them to maintain theii' weight or 

 increase. The oysters thrive best upon the 

 living Protophyta and Protozoa. Those 

 fed upon oatmeal and flour after a time 

 sickened and eventually died. 



III. The deleterious effects of stagnation, 

 owing to the collection of excretory pro- 

 ducts, growth of micro-organisms, and for- 

 mation of scums upon the surface of the 

 water. 



IV. The toleration of sewage, etc. It 

 was found that oysters could, up to a cer- 

 tain point, render clear sewage-contam- 

 inated water, and that they could live for 

 a prolonged period in water rendered com- 

 pletely opaque by the addition of fsecal 

 matter; that the ftecal matter obtained 

 from cases of typhoid was more inimical 

 than that obtained from healthy subjects ; 

 and that there was considerable toleration 

 to peptonised broth. 



V. The infection of the oyster bj^ the 

 micro-organisms. The results of the bac- 

 teriological examination of the water of the 

 pallial cavitj' of the oyster, and of the eon- 

 tents of the rectum, showed that in the 

 cases of those laid down in the open water 

 of the bay the colonies present were 

 especially small in number, whilst in those 

 laid down in proximity to the drain pipe 

 the number was enormous (e. y., 17,000 as 

 against 10 in the former case). It was 

 found that more organisms were present in 



the pallial cavity than in the rectum. In 

 the case of the oysters grown in water in- 

 fected with the Bacillus typhosus, it was 

 found that there was no apparent increase 

 of the organisms, but that they could be 

 identified in cultures taken from the water 

 of the pallial cavity and rectum fourteen 

 days after infection. 



It is found that the typhoid bacillus wiU 

 not flourish in clean sea water, and our ex- 

 periments seem to show so far that it de- 

 creases in numbers in its passage along the 

 alimentary canal of the oyster. It would 

 seem possible, therefore, that by methods 

 similar to those employed in the ' Bassins 

 de degorgement' of the French ostreicul- 

 turist, where the oysters are carefully sub- 

 jected to a natural process of cleaning, 

 oysters' previously contaminated with sew- 

 age could be freed of pathogenic organisms 

 or their products without spoiling the oys- 

 ter for the market. 



It need scarcely be pointed out that if it 

 becomes possible thus to cleanse infected or 

 suspected oysters by a simple mode of treat- 

 ment which will render them innocuous, a 

 great boon will have been conferred upon 

 both the oj'ster trade and the oyster-con- 

 suming public. 



We desire to acknowledge the kind help 

 of Mr. W. I. Beaumont in making some of 

 the observations at Port Erin, and of Mr. 

 Andrew Scott at Liverpool. 



I 



ADDRESS OF THE PRESIDENT, SIR DOUGLAS 

 GALTON, BEFORE THE BRITISH ASSO- 

 CIATION FOR THE ADVANCE- 

 MENT OF SCIENCE {II.). 



The eai'liest Eeports of the Association 

 which bear on the biological sciences were 

 those relating to botany. In 1831 the con- 

 troversy was yet unsettled between the ad- 

 vantages of the Linuiean, or Artificial sys- 

 tem, as contrasted with the Natural system 

 of classification. Histology, morphology, 

 and physiological botany, even if born, were 



