fish of all those more than one year old. The number of each age 
in such a haul would be—32 in their second year, 16 in their third, 
8 in their fourth, 4 in their fifth, 2 in their sixth, and 1 
in its seventh year. It is, however, quite unlikely that we would 
ever have such a regular result. The numbers that we actually 
obtained in our haul are not very different from what would be 
expected if the death rate of the plaice in Passamaquoddy bay were 
just 50% per year, as in our supposed case. In fact the numbers 
found indicate an even higher death rate, because there are more 
fish in their second year and fewer of the older fish than would be 
expected with such a death rate. We are quite conservative in 
concluding that the death rate in Passamaquoddy bay is at least 
50%. We have shown this graphically on the right hand side of 
figure 14, where we have represented successive years by horizontal 
lines placed one above the other, the relative number in each year 
being indicated by the length of the line. The thick part of each line 
shows the relative number of each age actually found, while the 
parts between the two curved lines give the relative numbers in the 
stock when the death rate is 50% or one-half per year. The corres- 
pondence between the two is quite as good as could be expected. 
A plaice has indeed a very small chance of reaching an age greater 
than seven years in this bay and in fact we have up to the present 
found, with a single exception, none of greater age. 
The stock in the gulf of St. Lawrence is quite different. 120 
plaice captured in one haul of the net trawl] at a depth of 30 fathoms 
halfway between Cheticamp and the Magdalen islands in Sep- 
tember, 1917, were of the following ages: 
| Age in years........ ae 516 CE ae o 
Numberson pice) ai couniemcs 4aiqe ate nae 
| Age iniyears.. gee 14 e He 2 Fs p20 [21 es (23 Ps 
Number of plaice... .| 3 Pe te? pes ae es: Lilet 
Although for the many ages represented the numbers are too 
small to give the best picture of the conditions, it is quite clear that 
there is a very gradual decrease in the number with age. As the 
proportion of older fishes is so high, the death rate in this region 
28 
