56 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



Wickford, was kept under observation throughout the summer. On 

 the 9th of August, after they had become considerably thinned by 

 the crowding out process, 12,500 specimens were gathered from one 

 square yard by means of a rather coarse sieve. A large number of 

 smaller specimens were probably lost through the meshes of the 

 sieve. On various dates the average size was calculated from a 

 considerable number of specimens. When first observed, on July 

 4th, the average length was 6.1mm. {j of an inch); a month later, 

 on August 4th, they had more than doubled this length and meas- 

 ured 13.9mm. (^+ inches); on September 30th, the average length 

 was 23.7mm. (| inches); they were then about three months old. 



Experiment No. 2. On July 6th and 9th of the same year, 

 clams to the total amount of a pint and a half (about 2,000 speci- 

 mens) were taken from the above set and sown on the surface of a 

 box of sand and distributed as evenly as possible; the box was kept 

 suspended about 18 inches below the surface of the water at the 

 houseboat. These clams were continuously submerged during the 

 months of July and September, and during August were exposed at 

 low tide occasionally, when the houseboat was ashore. They grew 

 very much faster than those which remained on the shore. For ex- 

 ample, on August 4th they averaged 21.8mm. (13-16 inches) in 

 length against 13.9mm. (^ inch) on the shore; and on Septem- 

 ber 30th 29mm. (1| fnches) against 23.7mm. (| inches) on the 

 shore. The difference was due to the more favorable location 

 of the transplanted clams; they were entirely unmolested and were 

 continuously under water in the tidal current, which was full of food, 

 and they lay night and day with the siphons expanded at the sur- 

 face of the ground. The two accompanying curves represent the 

 difference in the rate of growth between these two classes of clams. 



Experiment No. 3. Several specimens were taken from this 

 same set on July 19th, 1899, individually measured, and kept sep- 

 arate in flower pots placed under water at the houseboat. These 

 specimens measured from 8 to 12mm. (5-16 — 7-16 inches). About 

 seven weeks later, on September 10th, they were again measured, 



