Page:The Book of the Aquarium and Water Cabinet.djvu/137

Rh mouth, and afterwards draw it back, as a water fowl will draw its feathers through its bill to prepare them for resisting water.” I have now (July, 1856) some thousands of the larva of this and other species of gnats, and they are the most lively creatures in my collection. The flies come off in large numbers, and escape through the open window; or, if the window be closed, they swarm on the glass, and keep up a musical humming, closely resembling that of a swarm of bees at a distance.

A more elegant example of this kind of breathing apparatus is seen in the grub of the two-winged fly,

Stratiomys Chamæleon. The funnel tail spreads into a beautiful star of thirty distinct rays, and with this