88 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



which hide in the thicket, and that all the apparent plants are really animals. The 

 delicate star-like flowers are the vermilion heads of boring annelids or the scarlet 

 tentacles of actinias, and the thicket is made np of pale lavender bushes of branching 

 madrepores and green and yellow and olive masses of brain coral, of alcyonarians of 

 all shades of yellow and lilac and purple and red, and of red and brown and black 

 sponges. Even the lichens which incrust the rocks are hydroid corals, and the whole 

 sea garden is a dense jungle of animals where plant life is represented only by a few 

 calcareous alga? so strange in shape and texture that they are much less plant-like 

 than the true animals. 



The scarcity of vegetation becomes still more noticeable when we study the ocean 

 as a whole. 



On land herbivorous animals are always much more abundant and prolific than the 

 carnivora, as they must be to keep np the supply of food. Insectivorous birds are 

 very abundant, but they are not numerous enough to keep the plant-eating mollusks 

 and insects in check, and the devastation which is caused every year by the armies of 

 grasshoppers and locusts and herbivorous beetles and by other less conspicuous insects 

 shows that their natural enemies are not numerous enough to overtax their productive 

 power. 



The birds which feed upon grain and seeds and fruits are very abundant indeed, and 

 they sometimes gather at their breeding-grounds or places of assembly in innumerable 

 multitudes, but the hawks and owls which prey upon them are not very numerous. 



The small rodents, such as the rats, mice, squirrels, and rabbits are the most 

 abundant and prolific of animals ; but the small carnivora are so rare that their very 

 existence is known to few except naturalists and trappers. 



The homes of the wild sheep and goats., deer, antelopes, cattle, and horses support 

 these large mammalia in incredible numbers, but their carnivorous enemies are never 

 abundant. It is clear that if the destruction of the plant eaters exceeded their produc- 

 tive power, both herbivora and carnivora would disappear and terrestrial life would 

 come to an end. 



The animal life of the ocean shows a most remarkable difference, for marine ani- 

 mals are almost exclusively carnivorous. 



The birds which live upon the ocean (the terns, gulls, petrels, divers, cormorants, 

 tropic birds, and albatrosses) are very numerous indeed, so numerous that in many 

 parts of the ocean some are always visible in calm weather around the vessel where- 

 ever it may be. The only parallel to the pigeon roosts and rookeries of the land is 

 found in the dense clouds of sea birds around their breeding-places ; but these sea birds 

 are all carnivorous: most of them are fishers, and others, such as the petrels, scoop 

 up the copepods and pteropods from the surface. Even the birds of the sea shore 

 subsist almost exclusively upon animals, such as mollusks, Crustacea, and annelids. 



The seals pursue and destroy fishes; the sea-elephants and walruses live upon 

 lainellibranchs; the whales, dolphins, and porpoises and the marine reptiles all feed 

 upon animals, and most of them are fierce beasts of prey. The manatee is a vegetable 

 feeder, but it is not strictly a marine animal, since its home is in the mouths of great 

 rivers. 



There are a few fishes which pasture in the fringe of seaweed which grows in the 

 littoral zone of the ocean, and there are some which browse among the floating tufts 

 of algae upon its surface, but most of them frequent these places in search of the 



