126 BIRDS OF MIDDLESEX. 



breast-feathers, so placed as to curl over the eggs, 

 forcibly reminding one of the calyx of a tulip or 

 white water-lily. Although the hole was damp, the 

 platform of grasses and feathers formed a warm and 

 dry receptacle for the eggs, which were a pearly 

 white, and six in number." 



Mr. Gould is of opinion that the Sand Martin has 

 occasionally two broods in the year. 



One day in August, 1863, I saw an immense flight 

 of these birds on the ground near Kingsbury Reser- 

 voir. I was on the opposite side of the water when 

 I first found them, with my glass, and being in a 

 boat, rowed gently towards them. They allowed me 

 to approach within fifty yards, and I computed at 

 the time that there must have been about six hun- 

 dred birds congregated there. It was very curious 

 that all those that I could obtain a clear view of had 

 their heads turned in the same direction, which was 

 S.S.W. They never moved while on the ground, but 

 rose in a cloud as I continued to approach, and 

 settled again at a greater distance from me. I have 

 no doubt that they were congregating to migrate. I 

 saw a similarly large flock at the same place the 

 following year, on September oth, and Mr. Belfrage 

 has noticed a similar occurrence with regard to 

 Swallows on the banks of the Thames at Hampton. 



PURPLE MARTIN, Hirundo purpurea. With the 

 exception of one that was shot near Kingstown, in 

 the county of Dublin, there have only been two 



