Page:The Cornhill magazine (Volume 1).djvu/218

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are two larvæ (or grubs) of the common gnat. That large-headed fellow (A) bobbing about with such grotesque movements, is very near the last stage of his metamorphosis; and to-morrow, or the next day, you may see him cast aside this mask (larva means a mask), and emerge a perfect insect. The other (B) is in a much less matured condition, but leads an active predatory life, jerking through the water, and fastening to the stems of weed or sides of the jar by means of the tiny hooks at the end of its tail. The hairy appendage forming the angle is not another tail, but a breathing apparatus.

Fig. 7.

Larvæ of the Gnat in two different stages of development (Magnified).

Fig. 8.

Cyclops

a large antennæ; b smaller do.; c egg-sacs (Magnified).

Fig. 9.

Daphnia: a pulsatile sac, or heart; b eggs; c digestive tube (Magnified).

Observe, also, those grotesque Entomostraca,[1] popularly called "water-*fleas," although, as you perceive, they have little resemblance in form or manners to our familiar (somewhat too familiar) bedfellows. This (Fig. 8) is a Cyclops, with only one eye in the centre of its forehead, and carrying two sacs, filled with eggs, like panniers. You observe he has no legs; or, rather, legs and arms are hoisted up to the head, and become antennæ (or feelers). Here (Fig. 9) is a Daphnia, grotesque enough,

  1. Entomostraca (from entomos, an insect, and ostracon, a shell) are not really insects, but belong to the same large group of animals as the lobster, the crab, or the shrimp, i.e. crustaceans.