great numbers as was the case of the mosquitoes. The maggots 

 seem to be preferred over the worms by trout and bass but bullheads 

 are active eaters of pollution worms. 



The larvae of certain midges' (Chironomus), commonly known as 

 blood worms, also appeared in some numbers in the polluted earth 

 ponds. They are to be reported upon at a future time by another 

 person. 



The three forms of micro-crustacea, namely, Scapholeheris, 

 Cyclops and Canthocamptus, appeared abundantly in earth ponds 

 when the dosage was very light and also in heavily dosed earth ponds 

 after the polluting materials had been largely decomposed. They per- 

 sisted in rather dense cultures during the greater part of May and 

 June and again in late July and early August. The dosage best 

 suited for the development of these forms has not yet been deter- 

 mined. 



Before concluding these notes it is well to state that success was 

 attained in those ponds only which were practically water tight. Even 

 a slight change of water, as occurred in newly built earth ponds 

 through seepage, was enough to leach out the elements concerned in 

 fertilizing the pond and attracting mosquitoes for the purpose of 

 tgg laying. The conditions must thus be as stagnant as it is possible 

 to make them. 



Discussion. 



Mr. G. C. Leach, Washington, D. C. : Dr. Embody, have you ever ex- 

 perimented by placing the milk around the edges of ponds containing the 

 fish and noting the development of the mosquitoes? 



Db. Embody: No, we have never tried that. I do not know whether 

 the development of the mosquitoes would be harmful at all, but if you 

 use too much milk you may pollute the water beyond the degree of safety 

 to the fish. 



Me. Leach : Possibly that could be determined and the proper amount 

 put in so the development of the larvse would not be too great and they 

 would not get beyond control. 



De. Embody: Of course, you cannot control the mosquitoes in a large 

 pond as you can in a small pond. I do not think this would work suc- 

 cessfully in a series of very large ponds, but one could control them very 

 nicely in a series of small ponds. By having several ponds, with the 

 culture started at various times, you could simply have a rotation of 

 ponds, feeding the larvae from one while they were developing In the 

 others. 



Me. J. W. TiTCOMB, Albany, N. Y. : Dr. Embody, have you considered 

 the cost of producing this kind of food as compared with other kinds? 



Db. Embody : No, we have not reckoned the cost of producing the food 

 on milk waste. 



Me. Leach : If applied to the raising of young bass, a series of small 



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