A MIGHTY ATOM 229 



and claiming the distinction of being the only 

 fresh-water fish found in that region feed largely 

 upon the larvae of mosquitoes, and thus serve to 

 put a check upon the spread of the disease which 

 the mature insects disseminate by piercing the 

 flesh of human beings with their germ-carrying 

 stings. This discovery has been turned to good 

 account, and some years back arrangements were 

 made between the Colonial Office and the London 

 Zoological Society for the latter to keep a supply 

 of the little fish in order that some of them might 

 be exported, from time to time, to our various 

 possessions abroad where much sickness is due to 

 malaria. In October, 1908, the first consignment 

 of millions, numbering one hundred and twenty 

 individuals, left the Zoological Gardens for Uganda ; 

 there to be acclimatised and accomplish their 

 errand of mercy. Needless to say, the task of 

 conveying the fish, in the first instance from 

 Barbados to London, and then again to Uganda, a 

 total distance of nearly ten thousand miles, was a 

 matter of some difficulty, and the method of packing 

 them had to be thought out with great care. Empty 

 kerosene tins were eventually made use of for that 

 purpose, each one of which was enclosed in a larger 

 wooden case, and, finally, a layer of two inches of 

 sawdust was placed between the two in order to 

 prevent undue jolting and to keep the water within 

 the tins at an even temperature. 



Numbers of these mighty atoms have since been 

 exported to British Guiana, Bolivia, and the 

 Malay States ; and, according to reports, they have 



