88 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. IX. 



slender with two propeller-like blades at the end to assist its movements, for 

 it is still active, but, more singular still for a pupa, it breathes now, not through 

 a tube at the tail as formerly, but through two projections which it has been 

 provided with, which are situated on the top of the thorax, so that when it 

 rises to the surface of the water to breathe, it holds its head up now — a won- 

 derful change of habit in so short a time ; whilst living in this state, it also 

 enlarges, but does not feed. Having thoroughly matured, it is now ready to 

 change its aquatic life for an aerial one. The pupa comes to the surface of 

 the water, the thorax rising above it, the hinder part straightens out, and 

 almost immediately the pupa-case bursts on the top of the thorax, and the 

 head of the mosquito appears in the opening ; by a contracting and expanding 

 of the abdominal segments, the head and thorax are pushed forward and out 

 sufficiently far to free its legs, when it feels for a support which may be the 

 pupa-case which now floats on the water as a boat. The wings now expand, 

 the abdomen is withdrawn from the case, and Culex pipiens is off on other 

 business. The whole time required for this last transformation is a minute or 

 less. The length of its preparatory life is variously estimated, the weather 

 having a powerful influence — a month is considered quite sufficient. Three 

 or four days to mature the eggs, fourteen or eighteen for the larval 

 stage, and five to seven for the pupal. But Prof. Riley says : " Their 

 development is rapid, and with one species at least it has been ascertained 

 that the entire life-round from egg to adult is undergone in less than two 

 weeks." 



As soon as they have got their wings they make for the thickest vegetable 

 shade within reach. It is said that they will fly for miles inland, but never 

 fly far over water. We read of travellers on the South American rivers, that 

 they prefer to pass the night in their small boats anchored out on the river, 

 rather than attempt to sleep on shore ; willing to run the risk of being 

 devoured by alligators in order to escape the certainty of it by mos- 

 quitoes. 



Culex pipiens is a frail and delicate creature to be possessed of such a vicious 

 and blood-thirsty disposition. But here it must be stated that the sexes differ 

 in this respect. It is the female only that bites ; she alone is responsible for 

 all the evil reputation which has been attached to the species ; the male has 

 not the power, even if he had the will, whilst her will and power seem to 

 be commensurate. 



The mouth-parts of the female constitute a wondrously elaborate and com- 

 plex apparatus, which no verbal description can do justice to. What appears to 

 the naked eye to be a single sting is composed of no less than seven distinct 

 and separable parts. What is taken for the sting is only the sheath in which 

 the sting rests when not in use. Two of the parts are barbed at the point for 



