GROWTH AND REARING OF FOOD-FISH. 369 



apparently eateu, the shrimp larv« (Mysis stage) certainly were 

 attacked ; and from the fact that the young lobsters attack and 

 devour each other it is probable that Decapod larvae form at any 

 rate part of their usual food. The contents of a tow-net taken 

 near the Eddystone on August 6th, which held a young lobster, 

 consisted chiefly of Megalops and Mysis stages of Decapoda.* 



The qualification for success in all experiments of this kind is the 

 reproduction, on a small scale and under the control of the experi- 

 menter, of the essential factors in the environment of the animal to be 

 reared. The conditions which seem to us most likely to yield success, 

 both in hatching fish and lobsters, are the following : — The establish- 

 ment of a large and deep pond (say 1000 square feet in area, and 

 2 — 3 fathoms deep at some places) on a rocky coast, the levels beino- 

 so arranged that it should stand always about four fifths full, while 

 the remaining fifth should fill through filters on the top of ordinary 

 and spring floods, emptying slowly on the ebbs. A flora should be 

 allowed to form in the pond for a year or so before it is required 

 for hatching purposes ; and all predatory animals should of course 

 be kept down. At a higher level than this pond should be two or 

 three lesser ponds, kept well stocked with breeding animals whose 

 larvge are likely to serve as food (crabs and shrimps), communication 

 with the lobster pond being maintained by guarded siphons which 

 would carry over the lai-vee, but not the adults. While these would 

 supply one element of food, the daily tide would bring an additional 

 quantity of pelagic organisms, which could be supplemented by the 

 tow-net, and, if necessary, by artificial food (crushed crab, &c.). 

 The ova and embryos of common fish would probably prove a most 

 appropriate pabulum, cheaply and easily obtainable by artificial 

 fertilization ; but we had no opportunity of experimenting with 

 them during this hatching season. 



The mere hatching of the eggs of the lobster, whether they are 

 left on the mother, or are stripped from her and hatched in appro- 

 priate apparatus, presents, of course, no difiiculties ; it is easy to 

 turn myriads of young lobsters loose in the sea with a very small 

 expenditure ; but the general belief that over-fished grounds can be 

 replenished in this way is still open to very serious criticism. There 

 is as yet no proof that this procedure has produced or can produce 

 any effect whatever in restocking depopulated areas. We do not 

 desire to discuss this question here. Our experiments were a pre- 

 liminaty attempt to ascertain in what manner young lobsters might 

 best be reared in large numbers to the age at which they assume 

 the characters and habits of the adult ; to achieve this is simply 



* Young stages of the lobster have been rai-ely taken in the surface tow-net by the 

 Association both by day and by night, but never elsewliere thun at the surface. 



