Man and Nature 



431 



may be truly said to liavc "its hoart in its tlirnat." The 

 tail meanwhile is forming and liead and tail Ix'nd toward^ 

 each other until they almost touch, while Die yolk sack appears* 

 like a great tumor upon the belly of the young fish, which 

 soon begins to try its muscles in sjiasmodic jerks and 

 twists. Prior to hatching the little cMuhryo is surrounded 

 by the delicate and highly extensible membrane which sur- 

 rounded the egg. At time of hatching this membrane is 

 broken, the food stored in the yolk sack is soon absorbed, 

 and the young fish begins to "rustle for a living." At this 

 stage the fry may be set free in the river, or if suitable ponds 

 are available, they may best be kept at home and fed on 

 chopped liver, meat, milk curds, etc., for several months until 

 they are better able to take care of themselves. For the whole 



Developing Fish 

 Showing yolk sack. From Kunz & Eadcliffe, Bulletin of the U. S. 

 Bureau of Fisheries, Vol. 35, 



principle of fish culture is that a greater per cent of egg^ will 

 be fertilized artificially than in nature, and a larger number 

 of them will develop safely in the care of the hatchery than 

 if exposed to their hosts of natural enemies. 



While the seal and whale are not fishes, the Bureau of 

 Fisheries, on the basis of the old scriptural classification of 

 "beasts that swim," has included them and all other creatures 

 aquatic in the field of its activity. The fur seal industry is 

 but one among many examples of the influence of natural 

 wealth upon human history. The fur seals of the Pacific are 

 grouped in two main herds, those of the Pribilof, and those 

 of the Commander Islands. The former are part of Alaska 

 and the latter of Siberia. The former herd was discovered in 

 1786 by the Russian navigator Pribilof, whose name is borne 

 by the islands of his discovery, and the latter in 1741 by the 

 naturalist Steller who accompanied the ill-fated Beh)-ing on 

 his second and final voyage in 1741. A few years ago the 

 seals were threatened with extinction, the Pribilof herd having 

 suffered reduction from its original number of four or five 



