22 INLAND FISHERIES. 



EATE OF BUEROWING. 



A statement of the bearing- of the habit of burrowing on the 

 problem of clam-culture. 



A statement in tal)ulated form of experiments made to de- 

 termine the effect of varyino- conditions on the rate of 

 burrowing-. 



A summary of results. 



Conclusions. 



RATE OF GROWTH. 



The record of a series of new experiments made to ascer- 

 tain the rate of growth of clams of various ages planted 

 iTuder varying conditions. The record will be presented 

 in tabulated form, and the inferences drawn will be stated 

 in the text. 



FIGURES. 



A series of figures reproduced from life-size photographs, 

 showing some of the new results in respect to the rate of 

 growth of the clam. 



Breeding. 



How old are darns when tJiey Jirst breed? 



This iiroblem was left open at the time of writing the last Report, 

 but now can be definitely answered. 



The clams which were described in the last report as setting in 

 such abundance on Cornelius Island were kept under observation 

 throughout the year, and in Maj^ were found to be full of ripe 

 sexual products. On May 25, 1900, a large number were carefully 

 examined, and all were ready to spawn. In order to be sure that 

 the eggs were ripe, artificial fertilization Avas tried, and the result 

 was as satisfactory as it has ever been with clams. From 5 per 

 cent, to 10 per cent of the eggs developed normally. Both the 



