134 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



the early spring by the clam diggers. These reports have been num- 

 erous and are increasing and apply to those particular districts in the 

 upper part of the bay in which our lobsters have been liberated. 

 They have occasioned remarks of surprise by the fishermen, because 

 this region has been so long barren of small lobsters. Whether this 

 can be taken as good evidence of the effect of liberating in these 

 waters about half a million of young lobsters reared to the bottom 

 stage (the number up to two years ago) is at present of course entirely 

 a matter of opinion. 



ECONOMIC EFFICIENCY OF THE METHOD. 



At the end of an account of the method of rearing lobsters and of the 

 results actually attained, a brief speculation with regard to the 

 efficiency of the method from the economic standpoint may be 

 permissible. 



It is often true in biology that one can draw conclusions as to causes 

 and effects from observation and comparision of normal occurrences. 

 In the breeding of animals we seem to have a case in point. Fishes 

 which produce many thousands of eggs at a time, but whose young 

 are left almost utterly unprotected, often do not maintain so great a 

 numerical abundance as do other species (like the dogfish), which 

 produce only a very few individuals at a time, but give the young a 

 high degree of protection. 



While the relative values of the larval and fourth-stage lobsters 

 can not, for a long time at any rate, be determined accurately by 

 direct experiment, it would seem that a comparison of the breeding 

 habits of the lobster and the crayfish would, as Ehrenbaum has 

 pointed out, furnish data for a tentative valuation. Where the 

 lobster produces at one time 20,000 fry (Herrick got an average of 

 21,351 eggs from 414 observations of 12-inch lobsters), the crayfish 

 produces approximately 100 young (Ehrenbaum), which it protects 

 to a stage comparable with the fourth-stage lobster. Assuming, 

 then, that the 100 3^oung fourth-stage lobsters and the 20,000 newly- 



