BULLETIN OF THE UNITED STATES FISH COMMISSION. 115 
held captive by the shore from one year to the other, and were then 
found to give roe perfectly good for hatching. In consequence of these 
observations, all the parent fish for this year were kept in a reservoir 
in the hatchery ; and from them was got n manifold greater quantity 
of roe. This can be easily understood when I mention that, during the 
breeding season this year, notwithstanding the low temperature of the 
water by which more roe was lost than in any previous year, we had 
only 150 fish, against 400 to 500 the previous year, from which roe were 
obtained. The loss in the apparatus this year amounted to 52.8 per 
cent., against 39.3 per cent, in 1885. 
We must not conclude from this fact that the coldness of the water 
has a directly killing effect on either the roe or young fish. Such is not 
the case ; but the hatching period is so much prolonged, and necessi- 
tates the keeping of the roe for a longer time in the apparatus, where it 
is subjected to injury and loss. 
The time required for hatching cod eggs this year was forty- two days, 
whereas the longest time, in any previous year, was twenty-six days; 
the difference in the mean temperature was only 2.5° Reaumur. At a 
temperature of 4° R. [41° F.] it takes as a rule twenty -two or twenty- 
four days to bring out the young fish ; and as they then appear to 
be strongest and most vigorous, we may suppose this to be the tem- 
perature best adapted to their nature. If the water is warmer, as for 
example, 6° R. [45£° F.], the hatching will be done in fifteen or eighteen 
days ; but then the young fi&n are very frail and weak. The same is 
the case if the temperature is as low as 2° R. [36 F.] or lower. 
When the doubt regarding the possibility of hatching cod roe arti- 
ficially was clearly removed, another question was brought forward, 
namely, had the young fish, hatched in this manner, energy and power 
enough for further growth and development in the natural element ? 
It was useless to explain that the conditions were the same as for those 
hatched naturally ; that the temperature and saltness of the water, &c., 
were the same as in the sea ; that the fecundation of the eggs and the 
progress of hatching must absolutely be the same as nature’s arrange- 
ment, or else would have failed. The public wanted proof ; and as the 
same public kept the institution going by their subscriptions, there was 
no choice but to set to work and bring such proofs. 
A number of propositions were brought forward regarding the best 
course to adopt, and all had taken the economical question most 
strongly into consideration. That the same question had a prominent 
place in my calculations was natural ; but the main point with me was 
to guard against anything being done or adopted that would in any way 
endanger the complete success of the work. I looked upon the ques- 
tion from the standpoint that a failure in this case would place too 
strong a weapon in the hands of skeptics, and our fish-breeding institu- 
tions would come to an end. 
