56 THOMAS L. BANCROFT. 



so, or possibly in some cases fifty. The number of embryos that 

 are to be found in a drop of blood is some criterion of the number 

 of adults in the subject; if the embryos are scarce, it is likely 

 that there are few adult females, but if plentiful it is probable 

 there are many females. 



It is not known how long the embryo filaria lives in the blood, 

 probably it is several months, and probably the adult worms live 

 several years. 



Provided a filariated subject could prevent reinfecting himself, 

 it is very likely that in course of five years, he would be entirely 

 free from the parasites. To accomplish this, it might be wise to 

 emigrate to a country where there are no mosquitoes, and failing 

 that, to sleep under perfect mosquito-net bed curtains. 



Fortunately it is easy to rid the house of the Culex ciliaris; it 

 appears that this insect was introduced into Australia f it will 

 not go wild but always frequents habitations, breeding in recep- 

 tacles holding water in or about the house ; such receptacles 

 should be covered with gauze, net, perforated zinc or other material 

 to exclude mosquitoes ; cattle and poultry water troughs should 

 be emptied out at least every ten days, as by so doing, the mos- 

 quito larvae could never mature ; it takes fourteen to twenty days 

 from the mosquito egg to the perfect insect. 



In this investigation the following methods were found the best. 

 In breeding "house mosquitoes" it is necessary to obtain their 

 eggs or larvae. Galvanised iron washing tubs are convenient 

 vessels wherein to rear the larvae ; these are filled with fresh water 

 and placed in a shady spot; into them is put a handful of rotting 

 leaves and a small piece of flesh, preferably flesh that has passed 

 the putrefactive state in water, having been converted partly into 

 adipocere. When animal matter forms part of the diet, the larvae 

 grow faster and to a larger size. The larvae soon die should the 

 water become foul. In a fortnight or so the larvae will have 

 changed into pupae ; by means of a miniature scoop-net (the size of 



1 Proc. Linn. Soc. N. S. Wales, Vol. in., (Series 2nd) p. 1718. 



