﻿EXPERIMENTS IN MALARIAL TRANSMISSION. 527 



them from the ventral side, entangling their legs with those of the female, the 

 anterior pair being clasped around the thorax just back of the neck and the 

 middle pair being sometimes apposed to those of the female, sometimes entangled. 

 The act of copulation then takes place and may last as long as 30 seconds, the 

 male flying away to another part of the jar and the female proceeding to preen 

 herself after the manner of house flies. One male has been observed to copulate 

 with four or five females within as many minutes. None of these mosquitoes 

 have been observed doing so while on the wing, although it is not unlikely that 

 this does occur. 



Egg-laying. — The female when about to lay her eggs wanders on the wing just 

 above a place where the alg« are partly out of the water. She settles down 

 after a short time, walking somewhat rapidly over the surface, trying different 

 places with the tip of the abdomen. During this latter process the body is about 

 parallel with the surface of the water, while the head and palpi are inclined down- 

 ward. This is apparently the only time in this mosquito's life as an adult when 

 her head and proboscis are not in a line with the main axis of the body. When 

 the ovipositor encounters a small particle either of the alga? or of other material 

 projecting a short distance above the surface film, the female stops, palpates 

 with the tip of the body and almost immediately oviposits, going thus from 

 point to point till she has laid from ten to twenty-five eggs, she then stops for a 

 time to preen herself and to rest. Sometimes as many as seven or eight eggs will 

 be laid in a place. As the females which laid their eggs in captivity did so only 

 after having been fed a meal of blood, I suppose that those observed in nature 

 had also procured such food, although at the time of the observations their 

 bodies showed no signs of having blood within them. This may be due to the 

 fact that the eggs are laid some five or six days after the insect has fed. Those 

 mosquitoes which were observed laying in captivity were seen to have white 

 masses of eggs within the abdomen posteriorly, just before they were observed 

 to begin ovipositing. 



Habits of the female. — The female is much more active than the 

 male after copulation, which occurs after thirty-six hours of emergence. 

 Although she remains quiescent during the day, she is very alert 'after 

 5 o'clock in the afternoon. In both sexes the position of the body is 

 even more pronounced than that shown in drawings and sketches of 

 Anophelina? by various authors. In some instances individuals are seen 

 which have the body nearly at a right angle to the surface upon which 

 they are at rest and the posterior pair of legs is bent up over the back so 

 that the tarsi are not very remote from the dorsum of the thorax. The 

 female when disturbed flies off very rapidly in a straight line, and if 

 annoyed when in the act of inserting her proboscis for biting, she almost 

 invariably returns to the same point to renew the attack. When resting 

 upon a wall or other object the females of Myzomyia ludlowii Theob., 

 are not difficult to capture in very small vials, provided the extended 

 hind legs are not touched. These limbs are evidently intended to serve 

 the same purpose as the rostral hairs of animals like tigers, cats or mice. 

 They are kept in almost constant motion, sometimes one is elevated, 

 more frequently both. The males are somewhat more wary than the 

 females. 



