American Fisheries Society. 95 



they are born again, they know good and evil ; for the first time 

 the sense of fear is evident, and they retreat from danger ; there 

 is, in short, a purpose and direction in their activities which was 

 not ap])arent in the three earlier stages. 



The suddenness? and com]3leteness of these changes so con- 

 ducive to the safety of the lobsters gives much practical and 

 economic interest to the problems of rearing the young through 

 the critical period. The solution of these prol^lems would mean, 

 a great advance in the ethciency of general propagation of lob- 

 sters, and would be the first step toward artificial lobster culture. 

 With this in view a series of observations and experiments have 

 been conducted during the past three seasons by the United 

 States Fish Commission at Woods Hole, Mass., and by the Rhode 

 Island Commission of Inhind Fisheries at Wickford, E I. 



The problems in question can be arranged conveniently under 

 five heads as follows: 



1. What changes in structure occur in the early develop- 

 ment ? 



2. What is the duration of the first three stages? 



3. What are the general habits of life in the first four 

 stages ? 



4. What is the best method of supplying food ? 



5. What is the l)est means of protecting the fry in the first 

 three stages? 



1. What changes in structure occur during the early de- 

 velopment ? 



An excellent account of the structural changes from the Qg^ 

 to the fourth moult is to l)e found in F. H. Herrick's mono- 

 graph of the lobster, and it will hardly be necessary to discuss 

 them in this paper. 



2. What is the duration of the first three stages? 



The average period between hatching and reaching the fourth 

 stage for the experiment at Wickford was a little over twelve 

 days. In each experiment the average duration of the first 

 three stages, meaning the interval between the time of hatching 

 and the day upon which the largest number entered the fourth 

 stage, varies from nine to sixteen days. 



