68 THE ZOOLOGIST. 
have, it is but momentary. A Dragonfly (Libellula depressa) 
will return again and again to the strike of the net—nay, more, 
if, when caught and held captive by the wings, will take flies 
greedily from the hand of its captor. All feeling of fear in 
insects seems to be swallowed up in the insatiable desire for 
food. In the summer of 1909 I confined a Newt about a quarter 
erown in a small bottle of water, together with a Water-boatman 
(Notonecta glauca), for the purpose of taking home alive. I knew 
well the voracity of Notonecta, but thought the cramped confine- 
ment, added to the darkness of my pocket, and the inevitable 
shaking that must of necessity ensue, would have the desired 
effect, namely, of preventing the “‘ Boatman” from attacking 
the Newt. Not so, however, for on my return home nothing 
remained of the Newt but a lifeless sucked skin. The captive 
Whirligigs mentioned above had been subjected to the same 
treatment as Notonecta, and had hardly been in captivity more 
than a few minutes before the fly was offered to them, yet they 
seized upon it at once. Here, again, the ever-present desire to 
feed conquering (if any) all sense of fear. The eyesight of 
Gyrinus is remarkably keen, much more so than in a number 
of other insects, and nearly rivalling that of dragonflies. The 
shadow of an observer falling on the water, or a too near 
approach, is quite sufficient to send a party of them scattering 
in all directions. 
The expanding paddle-legs of the Whirligig are beautifully 
adapted for the functions they have to perform. Unfortunately, 
owing to the small size of the insect and its extreme rapidity of 
motion, these cannot be studied satisfactorily in the living 
insect, though every now and then something of their actions 
can be made out by watching the insect in a glass of water. 
Prof. Miall, in his delightful little book, ‘The Natural History of 
Aquatic Insects,’ has likened the structure of these paddle-legs 
to those ‘‘ivory tablets used for memoranda, which are held 
together by a pin, so that they can either be opened fanwise or 
closed in a moment.” It is these short paddle-legs that give so 
sreat an impetus to the swimming powers of Gyrinus. Dytiscus, 
with its ‘“‘feathered’’ rowing-legs, though it may (but I doubt 
this) swim as fast as Gyrinus, has not the same facility of 
turning, twisting, or rotating. Take, for example, two men, 
