NATURAL HISTORY OF THE STAR-FISH. 
215 
them the contents of the tow-net. During the last four days of June innumerable 
larvae of a marine worm ( Syllis ) were swarming at the surface, and on July 11 millions 
of the young of one of the sea-snails ( Littorina? ) were caught in the tow-nets. 
The clam, also, is one of those unfortunate animals whose larvae set at about the 
same time as the star-fish, and in the same places. The star-fish before they are 3 
days old show a predilection for young clams, which apparently does not diminish so 
long as any clams remain. Fig. 2 was drawn from life last summer by Dr. J. L. Kellogg, 
and represents a characteristic scene in the marine tragedy. 
In order to ascertain how fast the stars of the average size found upon the 
eelgrass would devour the young clams of average size, I plaeed one such star in a 
dish with 56 clams taken at random from the margin of a stone. The larger clams 
weie about the length of one arm of the star, and they ranged from this length to 
1 or 2 mm. The experiment was begun at 1.22 p. m. on July 18; at 5.40 p. m. 2 
clams had been devoured, each about the length of the arm of the star, and during 
the evening a third was eaten. At 8 o’clock the following morning 5 had been eaten, 
at 9 o’clock 6, and at 9.05 the seventh clam had been attacked. I was absent from 
the laboratory for the next 4 days, and, returning on the 22d, found at 6 p. m. 29 empty 
shells whose contents had been eaten by the star, which had grown considerably and 
was eating faster than formerly. The next day 39 empty shells were found, and on 
the following day 46 were empty, while 10 more had disappeared altogether, having 
doubtless been devoured, shell and all, some time during the week. To make sure 
that the clams were killed by the star and did not die from some other cause, a control 
dish of clams was kept, in which all the specimens lived. In six days a single star-fisli 
devoured over 50 clams. Both star-fish and clams represented the average size at 
this season. I regret that I did not record the exact dimensions of the star at the 
beginning of the experiment. Fig. 11 shows its approximate size at the end of the 
experiment on July 25. 
When we recall how exceedingly numerous star-fish are, and that they are found 
in the same localities with the young clams, the result of this experiment becomes 
still more significant. At this rate 600 stars from one netful of seaweed could devour 
30,000 clams in 6 days. The star-fish in a cartload of seaweed, if it contained 200 
small forkloads, would have the capacity for destroying over 6,000,000 clams in a week. 
. From the foregoing it appears that the star-fish set for the most part during the 
last few days in June and the first week in July, some as late as July 16. They 
remain upon the seaweed in immense numbers until about the 1st of August, when 
many of them are found upon the bottom. By August 15 the greater portion of the 
stars have left the seaweed and gone to the bottom. The young stars do very great 
damage, not only to the young oysters, but also to the young clams. 
The stars could be destroyed by hundreds of thousands in July by collecting and 
drying a few cartloads of seaweed taken below low-water mark. After the first 
week or two of July the collection of seaweed would do no injury to the clams. 
X. What is the ra te of growth up to sexual maturity? 
The observations and experiments bearing upon this question were made at the 
Kickemuit River, and these methods were adopted: 
(a) A large number of star-fish were kept under constant observation and were 
surrounded with natural conditions as far as possible. 
(b) Frequent observations were made on the stars in their natural environment. 
