404 MOSQUITOES OF NORTH 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 
with 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 larve in it, although I have searched 
repeatedly and diligently for them. I have always believed that the absence of 
mosquito larvee 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 larve 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 larve 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 larve 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 larve at the 
same time, and found that in such a case the goldfish invariably preferred the 
larvee. 
“Tt 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 
