RESISTANCE OF FISHES. 



333 



(15-17 c.c. per 1.) were the fatal factors, and illustrates the 

 relative dying order of the large and small individuals of the 

 species used. It will be seen that the larger fishes lived longer 

 per individual, but a shorter time per gram, than the smaller 

 ones. This is shown clearly in the last four columns. That the 

 dying time per individual varies directly, while the dying time 

 per gram varies inversely as the weight of the individual, is still 

 more clearly shown in Table II., which gives this relation for 

 two of the species, namely the rock bass (Ambloplites rnpestris} 

 and the common shiner (Notropis cornutus}. 



In Table II. the relation holds very closely in the case of 

 the shiner, but seems to break down in the case of the larger 

 individuals of the bass. This apparent variation is to be ex- 



TABLE II. 



SHOWING THE RESISTANCE OF DIFFERENT-SIZED FISHES OF THE SAME SPECIES 



TO Low OXYGEN (.i-.is c.c. PER LITER) AND HIGH CARBON 



DIOXIDE (35-50 c.c. PER LITER). 



pected in very large fishes of any species, however, for if the unit 

 weight of the fishes loses power of resistance with increase in age, 

 sooner or later there will come a stage in the life cycle, where the 

 increase in weight, which for a time offsets the decrease in 

 resistance, will diminish and perhaps stop altogether, while the 

 ageing process will go on. Thus the individual resistance 

 curve, which at first rises more or less rapidly, will, at some point, 

 reach its maximum and begin to decline. The fishes will then 



