. Outlines of zoology. Zoology. 296 PERIPATUS, MYRIOPODS, AND INSECTS. in the abdomen, of which the last is the largest. From the oesophageal commissures two visceral nerves are given off, which form in a somewhat complex manner the innervation, of gullet, crop, and gizzard. Besides the large compound eyes, there are other sensory structures—some of the hairs on the skin, the maxillae (to some extent organs of taste), the antennae (tactile and olfactory), the anal cerci (tactile), and possibly the oval white patches on the head. Alimentary Systetti.—(i) The fore gut (stomatodasum) is lined by
. Outlines of zoology. Zoology. 296 PERIPATUS, MYRIOPODS, AND INSECTS. in the abdomen, of which the last is the largest. From the oesophageal commissures two visceral nerves are given off, which form in a somewhat complex manner the innervation, of gullet, crop, and gizzard. Besides the large compound eyes, there are other sensory structures—some of the hairs on the skin, the maxillae (to some extent organs of taste), the antennae (tactile and olfactory), the anal cerci (tactile), and possibly the oval white patches on the head. Alimentary Systetti.—(i) The fore gut (stomatodasum) is lined by a chitinous cuticle continuous with that of the outer surface of the body. It includes {a) the buccal or mouth cavity, in which there is a tongue-like ridge, and into which there opens the duct of the salivary glands ; {b) the narrow gullet or oesophagus ; (c) the swollen crop ; {d) the gizzard. Fig. 96.—Transverse section of Insect. (After Packard.) h, Heart ; i'', gut ; «, nerve cord ; st^ stigma ; z'r, trachea ; 7y, wing ; f, femur of leg. with muscular walls, six hard cuticular teeth, and some bristly pads. There is a pair of diffuse salivary glands on each side of the crop, and between each pair of glands a salivary recep- tacle. The ducts of the two salivary glands on each side unite, the two ducts thus formed combine in a median duct, and this unites with another median duct formed from the union of the ducts of the receptacles. The common duct opens into the mouth. (2) The mid gut (mesenteron) is lined by endoderm. It is short and narrow, and with its anterior end seven or eight. 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 Thomson, J. Arthur (John Arthur), 1861-1933; Newbigin, Marion I. (Marion Isabel), 1869-1934; Smith, Preserved, 1880-1941. fmo. New York, D. Appleton & Co.
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
