Bull. U. S. B. F., 192 



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Fig. 70. — The contents oi one propagation basket at the end oi a season's growth of five and 

 one-half months. The mussels were of microscopic size when shed in the basket by the fish. The 

 arrangement in series shows the amount ol variation at this age under the prevailing condi- 

 tions. Reduced to five-twelfths natural size. 



