NATIONAL FISHERY CONGRESS. 221 



numbers of immature lobsters and of mature females nearly ready to spawn. The 

 canneries have been allowed to use smaller lobsters than those which are sent to 

 market, and we are told that if further restricted they could not exist. Whether this 

 is true or not I do not know, but it is surely folly to protect an animal in one direction 

 and allow it to be destroyed in another. 



We have now to speak of the artificial propagation of the lobster as a means of 

 maintaining or increasing the supply. In 1893 I tried to point out some of the funda- 

 mental errors which rendered the methods of artificial propagation abortive. The objec- 

 tions which were then made have never been answered or removed. 1 The difficulty 

 is that a false logic has dominated the whole subject, not only of the propagation of 

 the lobster, but of many of the true fishes, both in this country and in Europe. This 

 is shown by the fact that the number of eggs hatched has been taken as a direct test 

 of the efficiency of the method. The question of prime importance, which overtops all 

 others, what is the ratio between the number of eggs hatched and the number of young 

 reared, has been strangely left in the background or lost sight of. The following 

 sentence, which I quote from a report on the lobster industry in Canada, illustrates 

 the tendency to which I refer : 



The fecundity of the lobster is wonderful. Every female reaching the age of maturity emits 

 from 12,000 to 20,000 eggs every season. 2 



What is here implied is that because the lobster produces a large number of eggs 

 there must be a large number of lobsters raised from those eggs. This is a funda- 

 mental mistake. In the animal kingdom the production of a large number of eggs 

 points, not to a great number of survivals and consequent abundance of the species, 

 but to the great destruction of young, which makes a large number of eggs a necessity 

 in order to maintain the species even at an equilibrium. A blue crab ( Callinectes 

 hastatus) of medium or large size produces 4,500,000 eggs, or 157 times the number of 

 eggs laid by a lobster 13 inches long. Does this imply that the ratio of survival in 

 the crab is 157 times greater than that of the lobster or that the crab is 157 times 

 more abundant than the lobster at any point on the coast? Not at all. It rather 

 implies that the crab lays a smaller egg, has a longer larval period, and is subject to 

 far greater destruction by the elements of nature. In order to preserve its equilib- 

 rium, this expedient of producing a vastly greater number of eggs than can possibly 

 survive has been tried in nature and has met with success. In the tapeworm we 

 have an animal with individualized segments, capable of producing millions or even 

 hundreds of millions of eggs, and yet it is comparatively rare, since the chances for 

 survival of each of those millions of eggs is very slight, for in order to live the 

 embryo or larva must find its way by chance to the body of two particular and 

 distinct vertebrates. 



In the course of the struggle for existence among animals and their evolution 

 this chance of survival has been increased in other ways than by the multiplication of 

 ova, as by asexual reproduction seen in budding, or by acquisition of special habits or 

 instincts. In the vegetable world we are even more familiar with the great destruction 

 of seed; thus in the common elm, how many of the hundreds of thousands of seeds 

 which annually fall to the ground from a single tree are ever raised to maturity? 



1 The habits and development of the lobster, and their bearing upon its artificial propagation. 

 Bull. U. S. Fish Com. 1893, pp. 75-86. 



3 This statement is erroneous in that eggs are laid only every other year. 



