MOSQUITO BIOLOGY 85 



small pond about twenty-five by thirty-five feet and from six to thirty 

 inches deep. The central portion was grown over with water lilies, two 

 of the sides were bordered by a solid bank, while the other two were 

 sloped off and supported a thick growth of vegetation in the shallow 

 water. It appeared to be a typical Anopheles breeder, and a sweep of 

 the net through the water after these, brought up an egg boat of Man- 

 sonia perturbans. Thus we had at the very outset discovered at least 

 one of the breeding places of perturbans. A few minutes further search, 

 by gently pressing the vegetation beneath the surface of, the water, re- 

 vealed three additional egg boats. We next investigated a larger lily 

 pond on the banks of which Mr. Brakeley had caught his 300 adults in 

 fifty minutes. This was alive with small fish that were able to get to al- 

 most every point in the pond ; nevertheless, along the shallow borders, 

 I took egg boat number five. A sixth egg boat was taken from a sphag- 

 num pond where we fished for Corethrella brakeleyi. 



On August first I made a more thorough search of the small pond 

 wherein four boats had been found on the day previous. No part of the 

 water's surface was left unexamined, and in two hours fifty-nine egg 

 boats were collected. All were found for three feet out along the shallow 

 edges, where the vegetation was thickest and of a grassy nature. Along 

 the other two sides the lilies grew close up to the edges, and here and in 

 the center of the pond absolutely nothing was found. 



The egg boats were often clustered around a single stalk of grass, 

 forming a star of from four to nine points, one end of the boat being 

 drawn high up along the plant stem by capillary attraction, while the 

 opposite end pointed directly away from the center. 



Every part of the pond was searched for larvae as well as egg boats, 

 but with the exception of one young larva, apparently just out of the 

 egg, nothing was found. For a pond of this kind the water was remark- 

 ably free from insect or other hfe. In all, one small fish, three tadpoles, 

 two dragon fly larvae, fifteen small Dytiscid beetles, and one larva of 

 Uranotaenia sapphirina were taken from it. 



On August 6, an open swamp, six or seven acres in extent, at Trenton 

 adjoining Spring Lake, which was previously suspected of being the 

 source of the perturbans supply for the White City Park, was examined 

 for eggs. In such an immense area and with the species so much less 

 common than at Lahaway, the task was not a light one and at the end 

 of half a day's work only twelve boats were collected. Most of these were 

 fragments, found at widely separated places. On August 8 and 12, other 

 parts of this swamp were examined, and eggs were found all over; 

 though in certain spaces where the vegetation was not so thick or in 



