62 MALARIA 



One of the most valuable articles touching the con- 

 trol of mosquitoes by fish is that of Seal 1 for the Scien- 

 tific American, in which he makes the following state- 

 ments : "The goldfish is somewhat lethargic in habit, 

 and is also omnivorous, but there is no doubt that it 

 will devour any mosquito larvae that may come in its 

 way or that may attract its attention. The one great 

 objection is that they grow too large, and the larger 

 will eat the smaller of them." The same observer 

 concludes that "a combination of the goldfish, roach, 

 and top minnows would probably prove to be more 

 generally effective in preventing mosquito breeding 

 than any other." The top minnows mentioned are 

 Gambusia affinis and Heterandria formosa. In those 

 bodies of water kept free from mosquito larvae in Cali- 

 fornia, Mr. McGregor has observed that the following 

 three species are primarily concerned, viz. the Sacra- 

 mento chub, Leuciocus crassicandra; the Sacramento 

 pike, Ptychocheilus grandis ; and the Shiner, Lavinia 

 exilicauda. The Barbados "Millions" {Cyprinodon 

 dispar) has been found useful as a mosquito destroyer 

 in that country and elsewhere. 



In salt marshes the tiny killifishes (Fundulus) should 

 be given every opportunity to reach all parts of the 

 marsh. Where found they are, as a rule, very abundant 

 and are efficient as destroyers of mosquito larvae. 



1 Seal, William P., 1908 (May 30). Scien. Amer. Suppl Vol. 65, No. 

 i6gi,pp. 35I-35 2 - 



