92 LIFE IN THE SEA [PART I 



crustacean like the lobster, produces comparatively few offspring 

 indicates to us that some provision is made for the rearing, and 

 protection from enemies, of the eggs and larvae. Natural selec- 

 tion has taken two ways of combating the destruction of animals in 

 the sea. On the one hand enormous numbers of eggs are produced 

 only to be destroyed, while a few survive to maintain the species ; 

 and on the other hand few eggs and offspring are brought into the 

 world and all kinds of devices are elaborated for the protection of 

 these. 



Thus we find that fishes like the cod, whiting, turbot and 

 herring shed their eggs into the sea and take no further thought 

 for them. The ova of the first three fishes are shed into the sea 

 and drift about in the plankton, and though they are so pellucid as 

 almost to be imperceptible to the human eye, yet it is probable that 

 many pelagic animals feed upon them. Herrings deposit their eggs 

 on the sea bottom and then abandon them, and soon after hordes 

 of whiting come and gorge themselves on this nutritive material. 

 Herring, whiting, cod and turbot while they are in their larval 

 stages are among the most helpless of creatures that swim in the 

 plankton and while they are still microscopic in size many pelagic 

 animals must feed upon them. Then, with hosts of other young 

 fishes, they are stranded on the shore by the receding tide, and 

 being left in shallow sand pools, which soon dry up beneath the 

 heat of the sun, they perish miserably. Even when these fishes 

 have attained the age of juvenescence they are devoured by other 

 animals. Dozens of whiting furnish only one meal for a porpoise. 

 Cod prey upon turbot, whiting and herring ; and the whiting is not 

 infrequently cannibalistic in its proclivities. Skates, rays and 

 dogfishes are catholic in their tastes and prey upon all four of the 

 fishes instanced as examples of the reciprocal destruction of fishes 

 by each other. But the skates, rays and dogs are themselves 

 fairly free from enemies, and only the porpoises prey on the dog- 

 fishes and man on the skates and rays. The eggs of the two latter 

 fishes are enclosed in hard, horny indigestible capsules and are 

 not in danger of being eaten by other animals. They are laid on 

 the sea bottom and are not in danger of being stranded on the 

 shore. So too with the eggs of the oviparous dogfishes. All these 

 eggs are large and contain much food yolk, and when the young 



