Bill. U. S. B. F., 1919-20. 



Pl.ate XNIII. 



I^G. 1. — Seining fish from ovcrllow water fur infection with glochidia of mussels. 



Fig. 2. 



i lii i,ai^c iVi>in for mussel propagation. 



Fig. 3. — Transferrine fish to infection tank. Foreman in 

 boat is pouring the glochidia from a can into the tank. 



Fig. 4. — Sorting the fish for infection with glochidia. 



