. Elementary lessons in zoölogy : a guide in studying animal life and structure in field and laboratory . BiAGRAM OF Larva (x2): e, simple eyes on the front of the head; I, jointed legs attached to the three thoracic segments; sp, spiracle openings; pr, prolegs. wings. Powerful wing muscles are to be developed within them. Kill a large larva by placing a drop of chloroform upon its head, or by any other convenient method, and with a good lens examine : — 1. Its head^ as seen from the front and from be- neath. Make out: — (a) Ocelli situated on the front of the lateral prominences of the head.
. Elementary lessons in zoölogy : a guide in studying animal life and structure in field and laboratory . BiAGRAM OF Larva (x2): e, simple eyes on the front of the head; I, jointed legs attached to the three thoracic segments; sp, spiracle openings; pr, prolegs. wings. Powerful wing muscles are to be developed within them. Kill a large larva by placing a drop of chloroform upon its head, or by any other convenient method, and with a good lens examine : — 1. Its head^ as seen from the front and from be- neath. Make out: — (a) Ocelli situated on the front of the lateral prominences of the head. How many, and how ar- ranged ? (5) A lahrum, a little flap of membrane above the mouth. (c) A pair of rather prominent biting mandibles which meet by serrated edges. (c?) On either side of these a very rudimentary stump of an antenna^ here found situated lower on the head than in the perfect insect. (e) Below the mandibles, a pair of very rudimentary maxilloe. They are but fleshy prominences here, made recognizable by a pair of minute appendages (^palpi) at the tip of each. (/) Between and below the maxillae is the larger la- brum with its very minute rudiments of palpi, and a median appendage of special structure (a slender horny tube, which serves as a spinneret). Through it is exuded, from glands in the head, a liquid, which dries, immediately on exposure to the air, into the silken thread which the larva spins over the leaves. Compare this mouth with that of an adult. 2. The covering of the skin. What kind of out- growths can you find with a lens ? 3. Its thoracic legs. Make out: — (a) That they are jointed.
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1896
