REPORT OF COMMISSIONERS OF INLAND FISHERIES. 17 



can it accomplish the task set it — to fill up the gaps caused by years 

 of excessive fishing. 



In the particular case of the lobster about 30,000 new-born larvae, 

 which represent the average total mass of the brood produced by 

 one pair of lobsters during their lifetime, contain the potentiality 

 of only one pair of mature lobsters. For if under natural conditions, 

 from these 30,000 new-born larvae there are, after a lapse of 7 to 9 

 years, more than one pair actually living, there would arise an over- 

 population of the sea, as regards lobsters. The existing equilibrium 

 in the economy of nature demands this heavy mortality or life-risk 

 among the growing lobsters; or, to speak more correctly, on account 

 of the numerous dangers that encompass the growing lobster in his 

 particular mode of life, the creature mast be endowed by nature with 

 a germ-fertUity that shall suffice, in spite of the great decimation 

 which the struggle for existence entails, to guarantee, nevertheless, 

 the requisite posterit}^ 



We have simply to regard the germ-fertility of an animal, i. e., 

 the mass of germs which the species in question brings to maturity, 

 as an expression for the sum of the dangers which threaten the ani- 

 mal during its development up to sexual maturity- and the conse- 

 quent propagation. 



In the case of the oyster, which has a germ-fertilit}' of over a 

 million, and of the cod, which brings even three to nine million eggs 

 to maturity, their dangers must be materially greater than in the 

 case of the lobster, which is satisfied with a production of 20,000 eggs 

 on an average at each laying; and again, the lobster's dangers must be 

 greater than those of the crawfish, which brings only 60 to 120 eggs 

 to maturity. 



Now if artificial breeding aims to surpass the achievements of 

 nature, and bring a greater number of larvse or new-born to develop- 

 ment and full growth than nature is able to do, it is necessary first 

 of all to reduce the number and magnitude of the dangers and to 

 protect the growing animal, particularly in that period when its 

 life is especially threatened. 



.8 



