No. 397.] FOOD SUPPLY IN STARFISH. 21 
number of stars of the same age and size, transferred to a new 
car, he will not fail to notice that some of them happen upon a 
favorable food supply before the others, and in consequence 
grow at first much faster than the rest. Then, not only do 
these larger specimens have the better chance of getting food, 
but, if the animals usually preyed upon become scarce, the 
larger starfish do not hesitate to devour the smaller ones. It 
was noticed repeatedly that the variation in the rate of growth 
was much greater among the starfish whose food supply was 
limited than among those abundantly provided for. The 
immediate effect upon the rate of growth of the supplying 
and the withholding of food is demonstrated in the following 
experiments. 
One of the starfishes in the car which had grown most rap- 
idly up to August 18, when it measured 18 mm. (see curve r), 
was kept until September 26 with very little to eat. Dur- 
ing these five weeks there was no growth in this specimen 
(curve 2), but rather a slight decrease, although the largest 
specimen left in the car had doubled its length. 
Another small starfish (curve 3), which was caught in the 
tow net as a brachiolarian and “set” in the aquarium on 
June 28, was kept on a very small allowance of food until 
July 23, when it measured 2 mm. It was then fed occasion- 
ally on small barnacles, and on September 6 measured 5 mm. 
After this it was given an abundance of food, with the fol- 
lowing result: September 26, 12 mm. ; October 12, 21 mm.; 
November 5, 30 mm. 
Several other starfish which were caught in the tow and set 
in an aquarium at the same time with the last were kept on a 
small allowance until September 6, and were then apparently 
in good health, although they had grown but little. Fig. 2 4 
represents one of these at the age of about five weeks, and 
Fig. 2 B represents a well-nourished specimen of the same 
age, taken from the car. 
Two specimens (curves 4, 5) of medium size, 7 mm. and 
10% mm., respectively, were transferred, on August 3, 
from the original car, where they had been reared on barnacles, 
to an adjacent car. They were supplied with a bunch of 
