180 Thirty-Second Annual Meeting 



is he who has made a mistake, and failed to comprehend the 

 problem of the life of marine food-fishes, and not Professor 

 Baird and his successors, and that the burden of error is on his 

 shoulders and not on those of the Fish Commission. 



Marine food-fishes are enormously prolific because they are 

 exposed to so many dangers and enemies. Natural selection has, 

 in course of ages, brought about such an adjustment between 

 the natural destruction of the individuals of each species and 

 their birth-rate, that the number of mature individuals of the 

 species is about equal to the resources of the natural supply of 

 food, and remains constant on the whole, so long as the natural 

 conditions of their life remain vmchanged. But when a new dis- 

 ease, or a new rival, or a new enemy, which has not been pro- 

 vided for and guarded against by natural selection, invades their 

 home and comes to stay, the destructive effect of this new ele- 

 ment in their lives soon shows itself, even when its ra\ages are 

 so slight, as compared with the total number of violent deaths, 

 that it seems to be trivial and unimportant. Man is the mosi 

 resistless and insatiable of destroyers. The fear of him and the 

 dread of him is upon all the beasts of the field, and upon tlu' 

 birds of the air, and upon all the fishes of the sea, and upon 

 everything that moveth upon earth, but he is not a part of that 

 order of nature to which the l)irth-rate of marine aninuils has 

 been adjusted. iVs a navigator and a sea-fisherman he is too new 

 to have given natural selection time to have produced any com- 

 pensating adjustment; and the quickness with which he invents 

 new weapons of destruction, and improves himself in their use, 

 far outstrips the movement of this slow process of modification ; 

 for the time he has needed to progress from the bone fish-hook' 

 and the hurdle of rushes to the steam fishing vessel is as noth- 

 ing in the long history of species. It is, no doubt, true that the 

 whole number of mackerel and cod and herring which he de- 

 stroys is as nothing, when we compare it with the slaughter 

 wrought by blue-fish and porpoises and dog-fish, and other sea- 

 rol^l^ers, but this slaughter is provided for in the birth-rate, while 

 that which he works is not. While a numlier of food-fishes 

 greater beyond all computation than man destroys has Ix^en de- 

 stroyed by natural enemies each year for ages without any effect 

 upon their nKiiiidance, every on(> knows that wlicn man turns liis 



