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ZOOLOGICAL SOCIETY BULLETIN 



The present writer has been keenly in- 

 terested in the introduction of the domesti- 

 cated reindeer from its beginning, being per- 

 sonally familiar with the manner of life 

 of the Eskimo in the Bering Strait region. 

 Living in Alaska in summer and spending 

 the winter months in Washington during most 

 of the period when reindeer were being in- 

 troduced, he was in a position to keep in 

 touch with men in the field and to warmly 

 commend the enterprise to both congressmen 

 and churchmen at home. The late Dr. 

 Jackson, then agent of education in Alaska, 

 largely through his personal efforts, supported 

 by a few churchmen and public officials who 

 never lost faith in the plan to lift the Eskimo 

 to at least the level of the Laplander, carried 

 the work along from year to year in spite of 

 much opposition. The whole story, discour- 

 agements and all, would be well worth the 

 telling in much more space than that afforded 

 by this Bulletin. 



THE CURIOUS RELATIONSHIP OF THE 

 FRESH- WATER MUSSEL TO FISHES 



ANEW" and interesting work in aqui- 

 culture is now being carried on in the 

 Mississippi valley under the direction 

 of the United States Bureau of Fisheries. It 

 is based upon the fact that the propagation 

 of the mussel is dependent upon the presence 

 of fishes to which the young mussels may 

 attach themselves as parasites until they are 

 old enough to form shells and begin an in- 

 dependent existence. 



The large heavy-shelled mussels of this 

 region have been gathered in such numbers 

 for the manufacture of pearl buttons and also 

 for the valuable pearls they sometimes con- 

 tain that the supply is being exhausted and 

 the important industry dependent upon the 

 mussel is in danger of being broken up. 



It has become necessary to undertake the 

 artificial propagation of the mussel, and 

 restock the depleted waters of the Mississippi 

 and its tributaries. Preliminary investiga- 

 tion led to the establishment of a biological 

 laboratory at Fairport, Iowa, near the center 

 of the pearl button industry, where exhaus- 

 tive studies and experiments could be carried 

 on. Recent investigations have shown that 

 many of the numerous species of mussels are 

 dependent upon certain kinds of fishes as 

 temporary hosts for their young. The biol- 

 ogists now at work have demonstrated the 

 actual requirements in many cases. This is 



done by confining various species of fishes 

 in receptacles containing different species of 

 spawning mussels, after which they are sub- 

 jected to minute examination. 



The right species of fish must be found for 

 each species or genus of mussel, in order to 

 get profitable results. Young mussels attach 

 chiefly to the gills of fishes, and in some species 

 to the fins, during this early and critical 

 period of their lives. It is now practically 

 certain that all mussel spawn which fails to 

 find a suitable fish host, sinks to the bottom 

 and dies. The young mussels are in fact 

 temporarily provided with minute hooks for 

 attachment and are soon enveloped in the 

 external epithelium of the fish, where they 

 remain encysted until the shell begins to 

 form and they can safely drop off. 



All fishes are not equally susceptible to 

 these temporary mollusk parasites. Some 

 receive very few, others shed them too soon, 

 while others die as a result of carrying too 

 many. Practical work has already com- 

 menced at the government hatchery, and large 

 numbers of fishes, "infected" as it is called, 

 with young mussels, are liberated to stock the 

 public waters, as their "parasites" develop and 

 fall off. The "planting" of the mussels is 

 therefore left to the fishes. It is even possible 

 to send mussel-bearing fishes to waters outside 

 the Mississippi system and thus introduce 

 good shell-bearing species .elsewhere. This 

 has in fact actually been done in the upper 

 Potomac River. There is every reason to 

 believe that practical mussel culture is now 

 at hand and that valuable pearl-shell and 

 pearl-bearing mussels may be established in 

 various parts of the country. 



Years ago the methods of artificial fertili- 

 zation of the eggs of many kinds of fishes 

 were worked out, with the result that today, 

 hundreds of fish culturists in the service of 

 the federal government and the states, are 

 planting fishes by the millions. The benefits, 

 great as they are, would be still greater were 

 our streams not polluted by sewage and the . 

 fish-destroying wastes of all kinds of manu- 

 facturing establishments. 



Scientific investigations following the de- 

 pletion of the valuable sponge fisheries of 

 Florida, have led to means of artificial sponge 

 propagation. Great progress has lately been 

 made in the artificial rearing of lobsters. 

 All of these achievements in aqui-culture are 

 the result of biological inquiry with definite 

 ends in view. 



