Elementary text-book of zoology (1884) Elementary text-book of zoology elementarytextbo0101clau Year: 1884 ABANE1DA. 499 posterior lung sacs (Mygalidce) or into a system of trachea? (Argyro- neta, D//sdera). The anus is placed ventrally at the end of the abdomen, and is surrounded by -four or six wart-like pro- tuberances (fig. 395, Spw), the spinning or arachnidial mammillae, from which the secretion of the glands passes out. spnning- In front FIG. 394.—H, Leg nf the fourth pair of A ferox. Gi, Calamistrum. b, End of foot of Pfiileeun dirt/sops with two claws and pencil consisting of spat
Elementary text-book of zoology (1884) Elementary text-book of zoology elementarytextbo0101clau Year: 1884 ABANE1DA. 499 posterior lung sacs (Mygalidce) or into a system of trachea? (Argyro- neta, D//sdera). The anus is placed ventrally at the end of the abdomen, and is surrounded by -four or six wart-like pro- tuberances (fig. 395, Spw), the spinning or arachnidial mammillae, from which the secretion of the glands passes out. spnning- In front FIG. 394.—H, Leg nf the fourth pair of A ferox. Gi, Calamistrum. b, End of foot of Pfiileeun dirt/sops with two claws and pencil consisting of spatulate hairs (S). c, End of foot of Epeira diadeina • E, web-claws; 2V1, ambulatory claw ; Gb, toothed bristles (accessory claws) (after O. Hermann). of these protuberances there often lies a peculiar structure called the cribrellum, with a covering of very fine hairs (fig. 395, Or). The spinning glands (fig. 396) are tubes of various shapes : they open by fine pores on the surface of the spinning papiUse, and secrete a viscid material, which in the air hardens to a fine thread and is woven by the aid of the claws on the feet into the well-known spider's web. Nervous system (fig. 367).—Besides the brain, with the nerves to the eyes and che- licera?, there is a single, usually star-shaped gaiiglionic mass in the thorax, from which nerves pass to the pedipalpi and legs, and also to the abdomen. Visceral nerves have also been observed on the alimentary canal. As a rule there are eight, or more rarely are disposed in two curved lines or more
Size: 1311px × 1526px
Photo credit: © Bookworm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
