264 



MORRIS M. WELLS 



Note (table 4) that the normal fishes were negative to O.OIN 

 CaCl2, that with the small fishes this reaction had become posi- 

 tive by the end of a little over a month (fish No, 6) while the 

 larger fishes were still negative. Fishes Nos. 9 and 10 show the 

 reaction of fishes starved for almost four months. These fishes 

 were kept in running water and probably obtained a little food 

 but the successive weighings showed that the process of starva- 

 tion was a continuous one. Note the reversal in reaction of 

 fish No. 9. The first experiment with this fish shows it to be 

 slightly negative. On the next day it had become positive, as 

 was shown by two experiments, with the salt flow at one end of 

 the gradient tank in one, and reversed in the other. The weigh- 

 ings show that the fish had increased in weight since the day 

 before and this increase must have been due to the securing of 

 food in some way; the food had temporarily restored the normal 

 reaction. However, by the next day the weight had again fallen 

 off and the fish was once more positive to the salt, as is charac- 

 teristic for starving fishes. 



2. Reaction of starved fishes to low oxygen 



The results of the experiments with starved fishes (rock bass) 

 in low oxygen gradients are seen in table 5, which shows that 



Showing the reactions of normal and starved rock bass to low oxygen in a gradient . 

 Reactions are expressed in per cent of time in the halves of the tank {work done 

 at Chicago) 



