274 The " Water-Flea " Scare in our City. [Sess. 



bury, " can only live in moist situations," and in these iron 

 boxes are the requisite conditions of damp, dirt, and darkness 

 for their propagation and multiplication. Why they did not 

 appear as an invading army long ago should be the question, 

 rather than how they have come at this time. 



The further question has been mooted. Are the spring-tails 

 which have now been found in hydrants and water-cisterns 

 all of the same species or kind ? Certain " experts " have 

 answered that they are, and they have even been named as 

 Podiira aquatica. Indeed, soane science teachers, who ought 

 to know better, have spoken and written lately of poduras 

 and spring-tails as if the two terms were synonymous. All 

 poduras are spring-tails, but all spring-tails are not necessarily 

 poduras. Messrs Evans and Carpenter recorded in 1904 

 having collected and examined in all no fewer than sixty-one 

 species of spring-tails in the " Forth " district alone. Many 

 of these are, of course, rare ; but others, as we have already 

 seen, are very common. That Podura aquatica is now found 

 in our domestic water-supply is very doubtful. The authors 

 already cited say of it, " Locally common on the surface of 

 stagnant water : as yet we have met with it only in East 

 Lothian." Of the numerous specimens of spring-tails taken 

 from water-cisterns which I have seen, the great majority 

 were yellowish-white in colour, and totally unlike the blue- 

 black Podura aquatica. Probably there are more species of 

 these insects than one with us at present, and what these 

 are we may learn, with other interesting details, from the 

 Eeport of Dr Williamson, when it at length makes its 

 appearance. 



A few words in closing on the subject of water-cisterns. 

 The Sanitary Department continue to iterate, " Keep your 

 cisterns clean." These cisterns, however, are often so 

 awkwardly situated, and so difficult of access, that it requires 

 no small amount of courage and exertion to reach them. A 

 space of twelve or eighteen inches is all that is usually 

 allowed for the entrance to a cistern ; and struggling from the 

 top of a long ladder, it may be, to enter through such an 

 aperture, is a difficult and delicate performance, worthy of an 

 acrobat. It may be hinted, too, that far more dangerous foes 

 to the health of the community than harmless spring-tails are 



