A METHOD OF LOBSTER CULTURE. 239 
It is an interesting and important fact that the tendency to swim decreases 
rapidly during their sojourn in the fourth stage and also that they can be encour- 
aged to live on the bottom by being brought into contact with it. These facts 
have suggested two modifications in the usual procedure in liberating lobsters— 
first, that of holding the lobsterlings in special rearing cars for a few days after 
they reach this stage, keeping up the current in order to keep the lobsters sepa- 
rated and to keep their food in suspension, and, second, that of liberating them 
in such a manner that they will immediately touch the bottom, in which case 
they are not so apt to make swimming excursions through the water. An ingen- 
ious device for the latter purpose has been invented by Mr. Barnes. The young 
lobsters are sunk in barrels which have the numerous holes for their exit so cov- 
ered up that while the lobster can get out predacious fishes can not get in. 
It is comparatively easy to care for fourth-stage lobsters. Space and plenty 
of food are about the only requisites. Like the fry,they are cannibals in pro- 
portion as they are hungry and crowded together; but unlike the fry, they con- 
trol their own movements and go where they please, whether swimming, or 
crawling, or burrowing, and they have, moreover, a strong instinct of self- 
preservation. 
Fijth-stage lobsters ——There is much to be said in favor of rearing lobsters 
to the fifth stage before liberating them, and this is not difficult to do, but requires 
space. In some experiments conducted without great care 80 per cent were car- 
ried from the fourth to the fifth stage in large lots of several thousand. In addi- 
tion to the advantage in the matter of size, strength, and hottom-loving instinct, 
which favors the fifth-stage lobsters, an additional advantage lies in the fact 
that the duration of the fourth stage can be shortened by abundant feeding. 
Doctor Emmel showed in a most convincing manner that by feeding alone, all 
other conditions being identical, the duration of this moult can be varied from an 
average of eleven to an average of twenty-four days. 
Liberation of young lobsters—Every visitor at the rearing plant asks the 
embarrassing question, ‘‘ What proportion of the liberated lobsters live to grow 
up?” Only once was a definite and satisfactory answer given to this question 
and that by a new recruit on his first day’s duty. 
In 1901 when the experiments began to indicate that a large number of 
lobsterlings could most likely be liberated from our establishment, investiga- 
tions were started to find out whether the physical conditions of the waters of 
Narragansett Bay were such that the young lobsters could live here throughout 
the year. Of this there is now no doubt, for the specimens reared from the egg 
have year after year been kept over winter in cars sunk or floated in the harbor 
at Wickford. Several were kept for three successive years and finally were 
lost through accident. 
