. An introduction to zoology, with directions for practical work (invertebrates). 340 INTRODUCTION TO ZOOLOGY. also he does not usually sting and draw blood from a living prey as does his mate, but lives a harmless life, sip- ping the nectar of flowers. Correlated with this difiference in food and habit, we find a difference in the mouth-parts of the sexes. In the female, the lower lip or labium is much elongated, and is soft and deeply grooved, forming a trough in which lie five very sharply pointed, almost thread- like rods (Fig. 261). The Fig. 260.âThe Common Grey Gnat [Culex pipiens), in c
. An introduction to zoology, with directions for practical work (invertebrates). 340 INTRODUCTION TO ZOOLOGY. also he does not usually sting and draw blood from a living prey as does his mate, but lives a harmless life, sip- ping the nectar of flowers. Correlated with this difiference in food and habit, we find a difference in the mouth-parts of the sexes. In the female, the lower lip or labium is much elongated, and is soft and deeply grooved, forming a trough in which lie five very sharply pointed, almost thread- like rods (Fig. 261). The Fig. 260.âThe Common Grey Gnat [Culex pipiens), in characteristic attitudes â when at rest. The male above, the female below. The actual length of body is -^ of an inch. two finest of these correspond to the mandibles (Fig. 261, mnd); the two slightly coarser rods, which have ser- rated tips, to the maxillae (Fig. 261, mx), and the fifth unpaired rod to an outgrowth of the roof of the mouth, not found in other insects, and called technically the " hypopharynx " (Fig. 261, hypo). The labial trough is closed above by the upper lip or labrum, which is also long and slightly grooved, and thus forms with the labium a flexible tube. The tip of the labium ends in two little fleshy lobes which are pressed firmly on to the skin of her victim, as the gnat prepares to bite; the lancets are forced into the flesh, being kept steady by the terminal. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Lulham, Rosalie Blanche Jermaine. London, Macmillan
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Keywords: ., bookcentury1900, bookdecade1910, bookpublisherlondo, bookyear1913
