. Entomology for medical officers. Insect pests; Insects as carriers of disease. 270 ENTOMOLOGY FOR MEDICAL OFFICERS The hypostome (Fig. 120), which lies ventral to the chelicerae and is a prolongation of the ventral lip of the basis capituli, is armed on its ventral surface with files of strong recurved teeth ; it aids the chelicerae in boring through the skin of the victim and making good the hold. The pedipalps form an adjustable sheath to the more delicate mouth-parts just described, and are frequently hollowed along their inner surface for this purpose; when the mouth-parts are in action
. Entomology for medical officers. Insect pests; Insects as carriers of disease. 270 ENTOMOLOGY FOR MEDICAL OFFICERS The hypostome (Fig. 120), which lies ventral to the chelicerae and is a prolongation of the ventral lip of the basis capituli, is armed on its ventral surface with files of strong recurved teeth ; it aids the chelicerae in boring through the skin of the victim and making good the hold. The pedipalps form an adjustable sheath to the more delicate mouth-parts just described, and are frequently hollowed along their inner surface for this purpose; when the mouth-parts are in action the pedipalps are, as a rule, bent aside. The integument may be hard, or merely tough, or may. Fio. 120.—Kostrum of a Tick; left half of hypostome removed. be comparatively soft with localised chitinous indurations; embedded in it there are small glands, whose secretion is possibly acrid and defensive, and sparse hairs. On the ventral surface of the body the four pairs of legs are attached by broadly sessile coxae. Each leg consists of 6 segments (including the coxa), of which the last, or tarsus, is as a rule incompletely subdivided into two pieces, as also may be the 3rd segment, or femur; the tarsus ends in a pair of claws, which are borne on a slender stalk, with in some cases a membranous plate, or pulvillus, between them. In the cuticle of the extensor border of the tarsus of the first pair of legs there exists a narrow-mouthed pit lined with sensory hairs; this, which is known as Haller's organ, was. 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 Alcock, A. (Alfred), 1859-1933. London, Gurney & Jackson
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Keywords: ., bookcentury1900, bookdecade1910, bookpubl, booksubjectinsectpests
