334 PEOCEEDINGS OF THE SOCIETY. 



the only species of which the larva; survive the winter in England, and 

 any mosquitoes found up to about the end of May will most probably be 

 of this species. The larvjfi are fairly common in ditches near Bourne- 

 month, and are also to be met with in rain-water tubs which contain 

 much vegetable debris. 



By May these winter larvas have all developed. Early in June the 

 very small larvae of both A. maculiptnnis and A. hifurcatus, hatched 

 from newly-deposited ova, are easily met with in their proper habitats. 



The larvae of the two species may be distinguished by the arrange- 

 ments of the hairs on the clypeus, and the imagines by the wings of 

 A. maculipennis being spotted, while the wings of A. bifurcatus are 

 spotless. 



As considerable interest has lately been taken in mosquitoes, he 

 would indicate the methods he had found most successful in obtaining 

 them. It is much easier to obtain the larva? and to carry them through 

 the various stages to maturity than to search for the mosquito itself. 



The laivse of A. hifurcatus are to be met with in ditches which 

 contain a fair amount of water ; the larvfe of A. maculipennis in shallow 

 patches of water in the grass bordering the edges of country roads, and 

 more especially in shallow pools, in shady portions of forest ground, 

 notably in pools of the New Forest, in Hampshire. 



The larvae should be taken with a fair quantity of the water in which 

 they are found, together with a small portion of the debris from the 

 bottom to afford food. They may be seen at the bottom of the bottle 

 containing them feeding voraciously. 



The larva? should be kept in wide-mouthed glass jars, without any 

 covering, quite in the open, where they can get a little of the very early 

 morning sun and are fully exposed to external conditions of wind and 

 rain. 



If the larvae are kept inside the house they rapidly die off. They 

 should be watched daily until they pupate, the pup^ as they form being 

 removed into another jar of the original water, by a glass tube. They 

 require no food. The jar containing them should be tied over with a 

 piece of coarse muslin to prevent the escape of the mosquitoes after they 

 have emerged. By this method of full exposure to external conditions 

 nearly every larva may be developed. 



Sufficient importance has not been given to A. hifurcatus, which is 

 certainly the earliest to appear, and in some places, such as Bournemouth, 

 is quite as prevalent as the more frequently quoted A. maculipemiis. 



The Society's thanks were accorded to Mr. Waddington. 



Professor Benjamin Moore, F.R.S., read a paper on " Studies of 

 Activity of Light in Inorganic and Organic Systems." The author 

 gave a diseuse illustrated by experiments. The chief points dealt with 

 were : — 1. The natural modes of production of reduced organic com- 

 pounds, with uptake of energy. 2. The synthesis of formaldehyde from 

 carbon-dioxide and water by the action of light. 3. Condensation of 

 formaldehyde in light to form reducing substances, such as sugars. 



4. Reduction of nitrates by sunlight, accompanied by energy absorption. 



5. Growths of organisms in nitrate and nitrite-free media in presence 



