THE STOCK. 
It has been a matter of experience for a number of years that 
large plaice are very rare on the New Brunswick shore of the bay 
of Fundy. So true is this that were the net trawl not used the fish 
would be considered extremely rare, for it is quite the exception to 
take it on the line trawl. On the outer coast of Nova Scotia and 
in the gulf of St. Lawrence on the contrary there are many large 
fish and they are commonly taken on the line trawls. What is the 
explanation of this difference in the stock for different regions? The 
answer to this question is to be found in the marked difference in 
the death rate of the adult fish for these regions, since the rate of 
growth that we have found would tend to give a condition the 
exact opposite of what exists, namely there should be larger indi- 
viduals in the warmer water. 
An analysis of 66 plaice taken in one haul of the net trawl in 
Passamaquoddy bay on November 15th, 1917, gave the following 
result as to the numbers of the various ages. 
ENSMOMEM IV CATS S056 0.95 )9 shits: slat lak. Ue eal ee eet Me 4 5 6 
Number of ‘plaice... .5..... bev) 42 19 1 3 
We have in this case considered that the growth for the year is 
complete and we have given the age of the youngest as one year 
when in reality it was only seven months, and for the others simi- 
larly. Those in their first year were either too small to be retained 
in our net or they had not yet come into the bay, which explains 
the very small number obtained. Those in their second year were 
most numerous, then those in their third year. Of the later years 
there were very few. If the same number of young fish come into 
the bay each year and if conditions remain constant, the natural 
death rate will produce a condition in which there is a regular 
decrease in the number for each age, going from the youngest to 
the oldest. If for example 1,000 young fish settle in the bay each 
year, and if the death rate is one-half of the total population per 
year, we would have at the end of any year 1,000 fish in their first 
year, 500 in their second, 250 in their third, 125 in their fourth, 
62 in their fifth, 31 in their sixth, and so on. Let us now suppose 
that a haul is made and that it takes a representative sample of 64 
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