[27] THE SPANISH MACKEREL. AO 
Eggs of the sliad require an average of three to five days, while the 
period of -hatching for the other species handled is much greater. In 
water at 45° Fahr. eggs of the cod have been hatched in thirteen days; 
but when the temperature is reduced to 31°, as is not unfrequently the 
case in some of the bays and coves along the shores of Northern New 
England in mid-winter, the time of development is increased to fifty. 
days. The eggs of the salmon and whitefish require even a longer 
period. 
When first hatched the young fish are about one-tenth of an inch in 
length and are almost colorless. The food-sac, when compared with 
other species, is quite large in proportion to the body, the anterior mar- 
gin reaching nearly to the end of the lower jaw; and the tail is relatively 
much smaller. The food-sac, containing as it does the oil globule al- 
ready mentioned, is quite buoyant, and brings the fish to the surface of 
the water, where it remains belly uppermost for several hours. While 
in this condition it lies nearly motionless, though it occasionally indulges 
in spasmodic movements similar to those noticeable in its efforts to free 
itself from the shell. In a few hours it becomes slightly more vigorous, 
and moves about to a limited extent, going to the depth of an inch or 
more below the surface. When a day old the food-sac becomes less 
prominent, and also less buoyant, so that the fish experiences little diffi- 
culty in swimming at various depths. 
It is found that both eggs and fish are quite hardy, and that little 
difficulty need be expected in hatching the eggs or in transporting the 
fry to any distance desired. In one case eggs taken at six in the eve- 
ning were allowed to remain in a basin of water till the following morn- 
ing, when clean water was supplied, after which they received no fur- 
ther attention. A few hours later a large percentage of them hatched 
out, the fish being in excellent condition. 
About 40 young mackerel were confined in a goblet for two days 
without change of water before the first ones died. Others were placed 
in water that was allowed to cool gradually, and then suddenly trans- 
ferred to water ten degrees warmer, but this change of temperature 
did not seem to injure them in the least. In fact it seems probable that 
wrong impressions have prevailed for some time with reference to the 
care necessary for the eggs and young of different species, and further 
experiments in this line will doubtless prove that both are much more 
hardy than has been supposed. 
Haperiments in other places—When the necessary information had 
been gathered at Crisfield regarding the treatment of the eggs, it was 
thought desirable to proceed further down the bay, where the mackerel 
were more plenty, to find amore favorable locality for the establishment 
of a hatching station, as well as to enlist the sympathies of the fisher- 
men of that region. Accordingly we visited Hunger’s Creek, where the 
pounds of Dr. J. T. Wilkins are located, and spent a number of days in 
examining the catch and gathering additional information. Dr. Wil- 
