of the Salmon in Fresh Water. 



31 



TABLE VI. 



COMPARISON BETWEEN THE DIGESTIVE POWER AND THE ACIDITY OF THE 

 GASTRIC EXTRACTS, ARRANGED WITH REGARD TO THE MICRO- 

 ORGANISMS GROWN FROM THE STOMACH. 



In Chart I. the relationship between the acidity, peptic activity, and 

 bacterial contents of the stomach is graphically shown. 



The first three fish noted yielded no bacteria of any kind from the 

 alimentary tract, while their peptic activity,, which was tested in 

 common, was high, and the acidity of their common extract above the 

 average. Three fish yielded growths of moulds only, and presented a 

 much lower peptic power, but a similar acidity. Three also gave 

 evidence of the presence of moulds, along with a small number of 

 true bacteria. Their digestive power was above the average but less 

 than in the first three, while the acidity in their extracts reached 0'3 

 percent. On the other hand, in the seven fish in which no digestive 

 action was observed, the bacteria were very numerous, and the acidity 

 low. The latter set were almost all captured during the months of 

 July and August. 



These results appear to show that there is a direct connection between 

 the digestive activity and acidity of the stomach extract and the number 

 and form of organisms present. When the extract is acid and of con- 

 siderable digestive power organisms are either absent, or few in 

 number. When only a slight digestive power with a similar acidity 

 occurs, no organisms are present save moulds. Here the growth 

 of other organisms may be arrested by the growth of the moulds 



