96 American Fisheries Society 



opportunity to determine experimentally to what extent 

 this precaution affects the result. 



With the herring were infected a few mooneyes, Hio- 

 don tergisus, Le Sueur. Both species seemed to take the 

 infection but subsequent examination showed that the 

 glochidia were retained by the herring only. Although a 

 sensitive fish, the mooneyes stood the transportation 

 much better than the herring. 



The success of the simple method which we followed 

 was greater than anticipated. I had expected, in case it 

 failed, to try a live car and even an anaesthetic for the 

 fish during the infection. 



The glochidia used in the experiment were obtained 

 from mussels shipped by mail from Fairport, Iowa. Of 

 three shipments, two coming in cool weather were in fair 

 condition, the third in warmer weather was spoiled. In 

 this experiment the long shipment (time of transit 

 14 hours) was made for reasons of immediate con- 

 venience, a much nearer source of supply might have 

 been found, as the niggerhead mussel occurs in con- 

 siderable numbers in the river just below the outlet 

 of the lake. I found Q. ebenus in shell piles well up the 

 lake, but it is apparently quite rare. Its presence, how- 

 ever, in a natural state, indicated that the conditions were 

 such that the attempt to rear it experimentally in the 

 lake would be feasible. 



Upon completing the infection, Mr. Teachout, foreman 

 of the crew, was left in charge of the fish in the pound. 

 In accordance with instructions, at stated intervals, he 

 killed fish and forwarded the gills for examination. 

 Three shipments were made, the last being ten days af- 

 ter the last infection. Each lot showed the infection and 

 the latest showed considerable development of the young 

 mussels. In these, when prepared for microscopic exam- 

 ination, the following organs, liver, adductors, foot, and 

 gill-papillae, were visible. 



Gills of the fish killed immediately after the infection 

 show the manner of attachment and cyst formation 

 which are somewhat peculiar. In Pomolobus, we have 



