. Animal biology. Zoology; Biology. Outer dense layer Mic/cf/e, /oose layer Inner dense layer Chrysalis Cast-off larval '4 Skin A B Fig. 358.—Cocoon of the silkworm, Samia cecropia (Linnaeus). A, external appearance. B, section to show construction. From a specimen. involved is different, since receptors, adjusters, and effectors are all involved. The results differ in that the responses are distinctly more localized, and this adds definiteness and variety to the actions. This mode of behavior is first developed among the flatworms. 522. Instincts.—Instincts can best be defined as made up of a
. Animal biology. Zoology; Biology. Outer dense layer Mic/cf/e, /oose layer Inner dense layer Chrysalis Cast-off larval '4 Skin A B Fig. 358.—Cocoon of the silkworm, Samia cecropia (Linnaeus). A, external appearance. B, section to show construction. From a specimen. involved is different, since receptors, adjusters, and effectors are all involved. The results differ in that the responses are distinctly more localized, and this adds definiteness and variety to the actions. This mode of behavior is first developed among the flatworms. 522. Instincts.—Instincts can best be defined as made up of associated and coordinated reflexes. It is clear from this definition that it is difficult to draw a sharp line between the simplest instinct and a simple reflex act, but in the most complex of instincts we have a very characteristic type of action. The nature of an instinct may be well illustrated by a description of one which is very comphcated, such as the spinning of a cocoon by a cecropia silkworm (Fig. 358). If one keeps a caterpillar of this species in a box, giving it fresh food daily, it is a very docile prisoner, eating vora- ciously and, so long as fresh food is regularly supplied, seeming to have. 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 Wolcott, Robert Henry, 1868-1934; University of Nebraska (Lincoln campus). Dept. of Zoology. New York ; London : McGraw-Hill Book Company, Inc.
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Keywords: ., bookcentury1900, bookcoll, booksubjectbiology, booksubjectzoology
