NOTES ON THE WHIRLIGIG BEETLE. 71 
that it is, at any rate, double-brooded. I have very good reasons 
for assuming that oviposition begins as early as March, as I am 
certain a captive specimen was in the act of ovipositing, but, 
owing to an unfortunate accident, I was unable to verify this. 
The attitude this specimen adopted was exactly similar to that 
of Dytiscus when ovipositing. A stem of weed was grasped 
firmly by the front pair of legs, the insect lying lengthways on 
it. The abdomen was constantly in motion in an up and down 
direction. Finally, the extreme tip of the abdomen was fixed to 
the weed. At this juncture important business called me away, 
and I had not another opportunity of watching the insect. The 
pupa of Gyrinus has seldom been found, but Miall says:—* At 
the beginning of August the larva creeps out of the water by 
climbing up the water-plants, and then spins a greyish cocoon 
pointed at both ends.”* The ova apparently has not been 
described. 
Some naturalists have said that Gyrinus is capable of making 
a squeaking noise by means of its wing-covers against the end 
of the body, and this has been thought to be a call to others of 
its Own species. 
* * Aquatic Insects.’ 
