410 MOSQUITOES OF NOETH AMERICA 



tributed. They had proved very effective destroyers of mosquito larvas and also 

 of mosquito egg-masses. Later advices show that the good work is continuing 

 and that the experiment has been a great success. 



FISHES IN THE WEST INDIES. 



Girardinus poeciloides, a small top minnow, occurs very abundantly in Bar- 

 bados, where it is known by the popular name " Millions." This fish is very 

 small in size, the full-grown females measuring about 1^ inches in length, while 

 the male is much smaller. The female is dull in color, without conspicuous 

 markings, while the male is marked with irregular red splotches and has a 

 circular dark spot on each side. The fish is a rapid breeder and thrives and 

 multiplies in captivity, in water tanks, reservoirs and fountains, and garden 

 tubs in which aquatic plants are kept. They are much used in this way, both in 

 the towns and on the estates, to reduce the annoyance of mosquitoes. In 1905 

 this fish was introduced by the Imperial Department of Agriculture of the 

 British West Indies from Barbados into St. Kitts, Nevis and Antigua. In 1906 

 it was introduced into Jamaica, and in 1908 into St. Vincent, St. Lucia and the 

 city of Guayaquil in Eucador. An account of these introductions is given in a 

 pamphlet entitled " Millions and Mosquitos," by H. A. Ballon, issued in 1908 

 by the Imperial Department of Agriculture of the West Indies (No. 55). In 

 August, 1905, a number of fish were sent to Antigua in a kerosene tin. They 

 arrived in good condition and were kept in a tank at the Botanic Station until 

 they had sufficiently increased to be distributed. They were liberated in several 

 ponds and streams and increased so rapidly that the Country Board of Health 

 undertook the work of stocking all the ponds and streams of the Island. Three 

 years after the first introduction all of the more or less permanent water of 

 Antigua had been stocked, and Mr. Ballou states that many planters and others 

 have commented on the evident abatement of the mosquito nuisance in many 

 localities. At St. Kitts, the introduction was equally successful, but the local 

 government did not take up the distribution of the fish as in Antigua. In 

 Jamaica they were established with good results. Millions may be fed in 

 captivity on mosquito eggs and larvae, on raw beef or hard-boiled eggs, upon 

 small insects of any kind, and even upon cornmeal. They are readily trans- 

 ported short distances in a kerosene tin, with no other preparation than a wire 

 netting arranged near the top to prevent the fish from being thrown out if the 

 water is splashed about. 



The success of these West Indian experiments attracted the attention of the 

 sanitary authorities at the Isthmus of Panama, and some " millions " were in- 

 troduced into the Isthmus for the purpose of eating mosquito larvae. Similar, 

 and perhaps also the same species, already occurred on the Isthmus, but, never- 

 theless, the experiment was an interesting one. Under date of March 12, 1910, 

 Colonel Gorgas, Chief Sanitary Officer, wrote one of us, as follows : 



" Yours of March 1st is acknowledged. We brought over some of the minnows 

 from the Barbados and have been breeding them here for the last year. We have 

 also found some Girardinus poeciloides in the ponds and streams here that do 



