110 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



lobster rearing. This has been done in the following experiments. 

 I desire here to express my indebtedness to Mr. L. N. Wight, 

 through whose assistance these experiments were brought to a 

 successful conclusion. 



IV. Experiments to Determine the Comparative Value of 

 Beef and Clam for Rearing Newly Hatched Lobsters. 



a. Experiments and Results. 



In order to test the comparative food value and actual cost of 

 beef and clam, the following experiments were made in two of the 

 regular rearing bags of the lobster hatchery. 



These rearing bags are made of canvas. Each bag is about eleven 

 feet square and four feet in depth, with three windows of fine-mesh 

 copper wire netting, one window being on the bottom and one on 

 each of two opposite sides of the bags. A tw'o-bladed paddle, not 

 unlike a restaurant fan, is kept revolving slowly in each bag. The 

 current of water thus created by the paddle serves not only to change 

 the water in each bag, but also tends both to keep the food in cir- 

 culation and at the same time to prevent the lobster fry from 

 settling to the bottom. 



Two of the rearing bags were selected for the present experiments. 

 On July 11th, 40,000 lobsters which had just hatched were carefully 

 counted from the hatching bags; 20,000 of these first stage lobsters 

 were placed in each of the two rearing bags. 



All of the conditions in these tw^o rearing bags were kept as nearly 

 alike as possible. The lobsters in one bag were fed with the soft parts 

 of the clam, w^hich had been cut out from the shell and finely ground 

 in a meat grinder. The lobsters in the second bag were fed finely 

 ground beef. Food w^as given three or four times in every twenty- 

 four hours. In order to obtain an accurate estimate of the cost, the 

 food was carefully weighed. 



The lobsters were kept in the rearing bags until they had all 

 moulted to the fourth stage, June 24. These lobsters were then 



