404 MOSQUITOES OF NOETH AMERICA 



Mr. Wm. Lyman Underwood, of the Massachusetts Institute of Technology, 

 in " Science " for December 27, 1901, describes an interesting experience with 

 goldfish : 



" About six years ago at my home in Belmont, near Boston, Massachusetts, I 

 constructed a small artificial pond in which to grow water-lilies and other aquatic 

 plants, and also to breed, if possible, some varieties of goldfish — though the latter 

 object was a secondary consideration. The advisability of making this pond 

 had been somewhat questioned on account of its close proximity to my house and 

 the fact that such ponds are likely to become excellent places for the propagation 

 of mosquitoes. Nevertheless, the plan was carried out and the pond was stocked 

 wdth goldfish taken from natural ponds in the vicinity where they had been 

 living and breeding, to my personal knowledge, for a number of years. 



" The aquatic garden has proved a success and the goldfish have meantime 

 thriven and multiplied. Moreover, no mosquitoes attributable to the pond have 

 appeared and I have been unable to find any larvjB in it, although I have searched 

 repeatedly and diligently for them. I have always believed that the absence of 

 mosquito larvae from this pond was due to the presence of the goldfish, and I 

 have so stated in a paper ' On the Drainage, Reclamation and Sanitary Improve- 

 ment of Certain Marsh Lands in the Vicinity of Boston' in the Technology 

 Quarterly, XIV, 69 (March, 1901), as follows: 'In the water [of this pond] 

 are hundreds of goldfish that feed upon the larvae of mosquitoes and serve to 

 keep this insect pest in check.' ... I took from the pond a small goldfish about 

 three inches long and placed it in an aquarium where it could, if it would, feed 

 upon mosquito larvas and still be under careful observation. The result was as 

 I had anticipated. On the first day, owing perhaps to the change of environ- 

 ment, and to being rather easily disturbed in its new quarters, this goldfish ate 

 eleven larvae only, in three hours ; but the next day twenty were devoured in one 

 hour ; and as the fish became more at home the ' wigglers ' disappeared in short 

 order whenever they were dropped into the water. On one occasion twenty were 

 eaten in one minute, and forty-eight within five minutes. This experiment was 

 frequently repeated, and to see if this partiality for insect food was a character- 

 istic of those goldfish only which were indigenous to this locality, I experimented 

 with some said to have been reared in carp-ponds near Baltimore, Maryland. 

 The result was the same, though the appetite for mosquitoes was even more 

 marked with the Baltimore fish than with the others. This was probably due to 

 the fact that they had been in an aquarium for a long time before I secured 

 them, and had been deprived of this natural food. I also tried the experiment 

 of feeding commercially prepared ' goldfish food ' and mosquito larva at the 

 same time, and found that in such a case the goldfish invariably preferred the 

 la,rv8B. 



" It is not as generally realized as it should be that goldfish will thrive in our 

 natural northern waters. In my experience they can easily be bred in any 

 sheltered pond where the water is warm and not fed by too many cold springs, 

 and for many years they have been breeding naturally in many small ponds in 

 the vicinity of Cambridge, Massachusetts. 



" When it is once understood that these fish are useful as well as ornamental 

 and comparatively hardy, it is to be hoped that they will be introduced into 

 many small bodies of water where mosquitoes are likely to breed, and thus be 

 employed as a remedy for mosquitoes sometimes preferable to kerosene." 



The year 1908 in the Island of Cyprus proved to be the most malarious year 



since 1885. Careful examination of conditions was made by Dr. George A. 



Williamson, whose report will be found in the Journal of Tropical Medicine and 



