REPORT OF COMMISSIONERS OF INLAND FISHERIES. 103 



of oil, and as compared with other foods, being less subject to ready 

 decay, and easily kept floating in the water (p. 147*). 



II. Can the Present Feeding-Methods Be Improved? 



Although the soft-shell clam has thus been found to be the most 

 serviceable of the foods so far tried, the question still remains whether 

 the clam is in every respect the best available food. 



It is evident that the food which is to prove most satisfactory for 

 the purposes of lobster culture as developed at the Rhode Island 

 hatchery, must furnish: 



(a) A maximum rapidity in growth and moulting at 



(b) A minimum expense; 



(c) A minimum of objectionable material such as unedible tissues 

 Avhich decay and pollute the water; 



(d) Lightness, to enable the lobsters to secure the food before 

 it sinks, and 



(e) Certainty of a sufficient and constant supply. 



With reference to these requirements, the writer was asked by 

 Dr. A. D. Mead to further investigate the comparative value of 

 different foods. For this purpose the following experiments were 

 made during the summer of 1907: 



III. Experiments to Compare the Effect of Different Foods 

 upon the Growth of Fourth-Stage Lobsters. 



a. Methods. 



About 90 young lobsters were used in these experiments. These 

 lobsters had all moulted to the fourth stage on June 25, 1907. By 

 selecting a hatching bag in which the lobsters, perhaps 20,000 or 

 more, were all known to be in a given stage, it was possible to obtain 



* E. W. Barnes: Methods of Protecting and Propagating the Lobster, with a Brief Outline 

 of its Natural History. 36th Annual Report of the Rhode Island Commission of Inland- 

 Fisheries, 1906, p. 119-152. 18 Plates. 



