ANIMALS RECENTLY EXTINCT. 623 



from the smallness of the herd they have of necessity been very largely 

 inbred.* That inbreediug has something to do with the decrease of 

 the bison is indicated by the observed fact that many of the females 

 bring forth calves after having been infertile for several successive 

 years, but although it has been suggested that this might be helped 

 by the introduction of animals from the Caucasus, the remedy would 

 be difficult of application as well as expensive. As the herd is, or at 

 least was, divided into ten or twelve bands, each confined to a dif- 

 ferent part of the forest, perhaps some improvement might be effected 

 by judiciously crossing the members of these various groups. The 

 present rate of decrease is slow, and the Lithuanian herd will exist 

 for many years, even if the loss is not prevented. As for the Cau- 

 casian bison, protected as it is by nature as well as by man, it may 

 endure for centuries to come, and improbable as it once may have 

 seemed, be in existence long years after the American bison has ceased 

 to live even in tradition. 



THE RYTINA OR ARCTIC SEA-COW. 



(Rytina gigas.) 



The extinct Arctic sea-cow or rytina, an animal nearly related to the 

 existing Manatee and Dugong, played somewhat the same part iu the 

 exploration of the northwest coast of America that the buffalo did in 

 the settlement of the western plains. In the autumn of 1741 Bering, 

 returning from a voyage of discovery to the coast of Alaska, was ship- 

 wrecked on the island now bearing his name, this being the larger of 

 two islands lying about 100 miles from the coast of Kamchatka, and 

 known as the Commander Islands. The survivors of the expedition, 

 who were forced to remain on Bering Island for the ensuing ten 

 months, are frequently, though erroneously, said to have subsisted to 

 a great extent on the flesh of the huge sirenian discovered by them, 

 and described subsequently under the name of Manatus gigas. As a 

 matter of fact, the first rytina taken by Bering's party was not killed 

 until the 12th of July following the wreck, seal, otters, and later on, 

 far seals, furnishing a supply of meat. 



For our knowledge of the external appearance of the rytina, its 

 habits, and the localities it was wont to frequent, we are indebted to G. 

 W. Steller, the surgeon of Bering's command, and an enthusiastic 

 naturalist, who carried on his researches in spite of the privations attend- 

 ing a wreck, the inclemency of the weather, and the ravages of disease. 

 \s the Caribbean seal, described on a preceding page, presents the 

 anomaly of a member of an arctic family living in the tropics, the ry- 



k The Chillingham cattle ;.n\ in fact, subject t<> disease due to inbreeding, hut this 

 is scarcely to be wondered at, for the herd was once reduced to a single individual, 

 a cow with call', which proved to he a hull, and from this pair the present herd was 

 limit op. 



