298 TRANSFORMATIONS OF INSECTS. 
The Gyrinide are water beetles, and are well known by their 
peculiar habit of describing circles upon the water with wonderful 
rapidity. This extraordinary movement has given them their 
scientific name, which infers that they turn round, and we call 
them popularly Whirligigs, and the French YZourniguets. They 
are small beetles, the body is oval, and more or less convex, 
and the feet are perfectly organised for swimming; the middle 
and hind ones act as broad oars, and the front legs are used 
as rudders. They are generally of a very brilliant metallic 
bronze colour, and when the sun shines on them they look like 
pearls dancing on the surface of the water. Sometimes they 
stop short, appear immovable, and look as if they were easy to 
be caught, when all at once they disappear with the rapidity 
of lightning, darting about from place to place, whirling round 
and round, and finally plunging deep into the water. They pass 
the greater part of their existence on the surface, and watch 
for their prey below and look out for dangers above. Moreover, 
they occasionally snap up a passing fly; so Nature has given them 
four eyes, or rather their eyes on each side are divided, and the 
insects appear to have two eyes that look upward and two that 
look downward. When the whirligigs are caught they exude from 
their body a milky fluid of an extremely strong and disagreeable 
odour, which remains for a considerable time afterwards. 
The female beetle lays her eggs upon the surface of the leaves 
of aquatic plants. The adults disappear from the surface of 
ponds and rivulets when the weather becomes cold, and hide 
themselves at the bottom, under stones, amongst water weeds, 
and even in the mud. The larve are long, 
and the hard parts of their bodies are of a yellow tint. The 
head is small, and all the segments of the abdomen are furnished 
very thin, and white, 
upon their sides with long ciliated appendages, which act as 
swimming organs, and also as gills. The last segment has four 
movable hooks upon it, which enable the insect to jump. The 
larve, when full grown, are very active and voracious, and they 
get out of the way of danger by rapid jumping. About this 
time they leave the water and take up their abode upon the 
leaves of aquatic plants, spin a cocoon, and undergo their trans- 
formations. 
