. Animal activities; a first book in zoo?logy. Zoology; Animal behavior. 94 y4NIMAL ACTIVITIES. Under the abdomen near the cephalothorax find two openings to the air-sacs or rudimentary lungs. Summary of Drawings, {a) A spider seen from above X 3- (3) A front view of the mandibles X 5- (<:) A view of the top of the head showing the ocelli. {d) A hind foot much enlarged. The Spider's Activities. We have already con- sidered the activities of the grasshopper, classifying these under six heads. We have spoken of these six kinds of activities as the six functions of living things. In the spider
. Animal activities; a first book in zoo?logy. Zoology; Animal behavior. 94 y4NIMAL ACTIVITIES. Under the abdomen near the cephalothorax find two openings to the air-sacs or rudimentary lungs. Summary of Drawings, {a) A spider seen from above X 3- (3) A front view of the mandibles X 5- (<:) A view of the top of the head showing the ocelli. {d) A hind foot much enlarged. The Spider's Activities. We have already con- sidered the activities of the grasshopper, classifying these under six heads. We have spoken of these six kinds of activities as the six functions of living things. In the spider these activities are carried on by the aid of finely adjusted machinery -A Spider's Leg. which we can only describe somewhat roughly here. Taking Food. The devices by which spiders of different kinds procure their food are well worthy of study. Nearly all spiders are aided in this work by silken threads spun from their own bodies. In the lower part of the spider's abdomen there is a bag in which is secreted a glue-like substance which issues from the spider's body at will, and hardens on exposure to the air. The wart-like projections on the lower side of the abdomen near its posterior end are pierced with many hundreds of minute holes, through each of which proceeds a microscopic thread of the glue-like fluid we have mentioned. The wart-like projections are called spinnerets. The hundreds of tiny threads from the spinnerets are grasped by the spider's claws and twisted into several strands, which, woven together, make the fibre of which webs are built. A spider's thread, then, is a rope of several strands, and each strand is com- posed of many hundred lines, yet it is so light that it floats in the air, so strong that it easily holds up many times the spider's weight, so elastic that it does not. 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 p
Size: 1869px × 1336px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjecta, booksubjectzoology
