i8o 
BULLETIN OF THE BUREAU OF FISHERIES. 
crevice, or in its burrow in the mud, it waits until the victim is within reach of its 
claws. Though far less active and keen witted than many of the higher crabs, and 
sedentary in the sense of being restricted in its range, it is sluggish only at the period 
of the molt or in very cold weather. The sense of hearing is probably absent and that 
of sight far from acute, but this animal possesses a keen sense of touch and smell, possibly 
a sense of taste, and is quite sensitive to changes of temperature and light (see p. 184). 
MIGRATORY INSTINCTS. 
Adult lobsters never migrate up and down the coast at definite periods or in con- 
siderable numbers in any degree comparable to the semiannual movements of many 
fishes and birds; in April and May, however, they come in toward the shore, and again 
in fall retire to deeper water. Such migratory instincts as they possess are of a very 
diffuse type and are far from being generally displayed. The abundance of food and 
periodic necessity of molting and laying eggs, and the temperature of the water, may 
one and all enter with more or less force into bringing about local and restricted move- 
ments. When the question of food is paramount, lobsters will pass the winter in con- 
siderable numbers in the shallow waters of harbors, but usually only on a rocky bottom 
where food is to be found. The extent of their journeys is influenced by the slope of 
the bottom and the depth of water, as well as by the nature of the bottom itself, and 
varies in different sections of the coast as well as at the same point in different seasons. 
Movements of tagged lobsters . — In order to test the extent and rapidity of the adult 
lobster’s movements along the coast, as well as to and from deep water, some interesting 
experiments in tagging lobsters have been made by Bumpus {43) at Woods Hole, Mass., 
Mead and Williams (295) at Wickford, R. I., and by Meek (316) and Appellof ( 303 ) in 
Europe. 
In the summer of 1898 Bumpus tagged 479 lobsters from which eggs had been 
removed, and liberated them at various points about Woods Hole. Seventy-six of 
these were recaptured and the tags returned for identification. The valuable data thus 
obtained showed a great variation in the “migratory” impulse and remarkable rapidity 
of movement in individual cases. Some had not strayed far after gaining their freedom 
for from 3 to 4 weeks, being recaptured near the points where they had been set free, 
while others had moved at the daily rate of a mile for a period of 10 to 12 days. One 
of them which had been freed at Woods Hole on July 2 entered a trap at Cuttyhunk 
Island, 12 miles to the southwest, on July 13, having covered this distance in 11 days. 
It does not seem probable that such sporadic movements are determined by the search 
for more abundant food, or for more favorable conditions as regards the temperature 
and depth of the water or character of the bottom, but are to be set down to individual 
initiative and general restlessness of behavior. In this connection it would be interest- 
ing to learn whether the more sedentary or the more active individuals had showed 
any evidences of preparation for the molt, which is due in female lobsters shortly 
after the hatching of the eggs (middle May to middle July at Woods Hole). 
Tagging experiments were undertaken by Mead in the summer of 1902 and 1903 
at Wickford. Of the 16 released in the first season, the most enterprising traveler had 
