62 INLAND FISHERIES. 



auy time during the siimmer, after the stars are all set, there is a 

 great difference in size among them. To illustrate this point, 

 I arranged on August 18th a series of specimens taken from the 

 car and from the sea- weed, and photographed them at natural 

 size, by laying them down on the sensitive paper (with a thin 

 transparent film between), and then exposing. The variation in 

 size is shown in Fig. 20, the first five specimens having been taken 

 from the car and the last five from the sea-weed. This variation 

 in size is without doubt due much more to the difference in the 

 amount of food than to the difference in age. The following 

 experiments on the rate of growth of individual starfish support 

 this view. 



C. Rate of growth of individual starfishes kept under various 

 conditions. The starfish which was the largest of those in the 

 car on August 18th {compare Fig. 15) was kept in a dish A\dth only 

 a few very small barnacles for food. When taken from the car it 

 measured 18 m. m.; slightly more when fully expanded. On Sep- 

 tember 25th it measured 18 m. m., showing no growth. On Sep- 

 tember 2Gtli, thirty-nine days after it was taken from the car, it 

 measured between fifteen and sixteen m. m. In the absence of 

 food, therefore, it had lived and apparently was in perfect health, 

 but had probably diminished somewhat in length, as well as in 

 bulk. (Some allowance must of course be made for the contrac- 

 tion and expansion, as mentioned before.) During this time sev- 

 eral of the stars, smaller than this one, remained in the car and 

 grew to the length of 35 m. m. (Fig. 17.) 



A small starfish which was caught in the tow, and set on June 

 28th, was kept in the dish with many others until June 23d. On 

 this date it was placed in a small dish by itself and fed with small 

 clams and barnacles. Fig. 21 shows the growth of this specimen : 

 A. 2 m. m., July 23d ; B, 4 m. m., August 13th ; C, 4^ m. m., Au- 

 gust 18th ; D, 5 m. m., September Gth. On September Gth it was 

 transferred to a car where there was an abundance of small bar- 

 nacles. Fig. 21, E (12 m. m.), represents size on September 2Gth ; 

 F, 21 m. m., on October 12th; G, 30 m. in., on November 5. 



