164 



deep water. It was either to escape their In other words, the fishes of the Sand- 

 enemies or to extend their range for wich Islands are East Indian rather than 

 some reason ; as Mr. Garman puts it, American. This is no doubt caused from 

 "They have slid down," as it were to the the fact that the deep water between the 

 bottom of the ocean. islands of the American coast forms a 



In general, animals migrating will al- barrier which has always prevented the 

 ways move along lines of least resistance, two fish faunas from mingling with each 

 Some deep-sea fis-hes have a considerable other. Between Africa and the Sand- 

 vertical range. It is thought that some wich Islands this has not been the case, 

 move into shallower water to deposit A recent study of the fishes of the Gala- 

 their eggs or place their young in warm- pagos Archipelago shows its fauna to be 

 er water, and where the peculiar kind of American, though in what respect its 

 food they need early in life is the most fishes differ from those of our west coast 

 abundant. To study deep sea fishes is they resemble all the more the fishes of 

 difficult, and so little has been done that the Sandwich Islands. Two fish faunas 

 we not only know them imperfectly but will usually differ from each other if sep- 

 also know very little concerning their life arated by an impassable barrier ; espe- 

 histories. daily is this true if the barrier be older 



In February, March and April of 1891 than the two faunas. 



the United States Fish Commission Any barrier which prevents or hinders 

 steamer Albatross explored a portion of fishes in their movements from one body 

 the region between the coasts of Mexico of water to another will separate two 

 and Central America and the Galapagos more or less well-marked fish faunas. 

 Archipelago. Besides obtaining a large These barriers may be mountains, or 

 number of shore fishes, about nine hun- shallow water, as in the case of deep sea 

 dred specimens of fishes were secured, fishes ; deep water, as in case of shore 

 ranging from a depth of one hundred to fishes ; muddy or alkaline water, or water 

 twenty-two hundred and twenty-three of different temperature. Temperature 

 fathoms. This collection was carefully no doubt has far more influence in gov- 

 studied by Professor Garman, of Har- erning the movement of fishes than is 

 vard. He found the collection to contain generally believed. It plays an import- 

 one hundred and eighty species, eighty- ant part in guiding salmon up stream to 

 five per cent, of which were new to their spawning beds. It explains why 

 science. The bottoms of the oceans are they reach the head waters of some 

 far from level, and each deep basin has streams and spawn earlier than in similar 

 its own peculiar fauna. The shallower streams not far distant, but of different 

 parts of the sea prevent migration of the temperature. If you would know to what 

 deep water forms and no doubt living as extent fishes of one region differ from 

 they do in eternal darkness and in a tern- those of another, study well the barriers 

 perature near the freezing point, there is between the two regions, learn to what 

 little to induce them to much activity, extent and how long they have existed, 

 The fact that they are easily captured in consider the age geologically of the two 

 nets of comparatively small size would regions, and how fishes may have mi- 

 indicate that they move about slowly. grated to one or the other, and in a gen- 



Dr. Jenkins, who has lately studied the eral way you will have the key to the sit- 



fishes of the Sandwich Islands, informs uation, which a careful study of the fishes 



me that less than five per cent, are found is quite sure to verify. 

 on our American coast, while a large per Seth E. Meek, 



cent, is found all the way to the Red sea. 



