. Elementary entomology. Entomology. Fig. 45. Portion of compound eye of fly {Calliphora vomitoria), radial section f, cornea; /, iris pigment; «, nerve fibers ; iic^ nerve cells ; r, retinal pig- ment; t, trachea. (After Hickson, from Folsom) see distinctly only near-by objects. Large eyes, as those of the dragon- fly, give a wide field of vision, and numerous facets would give a greater distinctness of vision. In- sects' eyes are well adapted to detect motion, as a moving object affects the facets in succession, and motion is thus observed without moving the eyes. They are able to distinguis
. Elementary entomology. Entomology. Fig. 45. Portion of compound eye of fly {Calliphora vomitoria), radial section f, cornea; /, iris pigment; «, nerve fibers ; iic^ nerve cells ; r, retinal pig- ment; t, trachea. (After Hickson, from Folsom) see distinctly only near-by objects. Large eyes, as those of the dragon- fly, give a wide field of vision, and numerous facets would give a greater distinctness of vision. In- sects' eyes are well adapted to detect motion, as a moving object affects the facets in succession, and motion is thus observed without moving the eyes. They are able to distinguish colors and often respond quite definitely to them, but their color sense seems to have a different range from that of man, as ants are sensible to the ultra-violet Fig. 46. Illustrating mode of vision in compound eye " The light enters through the cornea. The rays which strike the sides of each tube or cone are absorbed by the black pigment which surrounds the tube. Ac- cordingly those rays of light only which pass through the crystalline cones directly (or are reflected from their sides), such as a-a', b-b', c-c', d-d', e-e', will ever affect the nerves at a', b', </, d', e'." (After Lubbock, from S. J. Hunter). 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 Sanderson, Dwight, 1878-1944; Jackson, C. F. (Cicero Floyd), b. 1882; Metcalf Collection (North Carolina State University). NCRS. Boston, Ginn
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Keywords: ., bookcentury1900, bookdecade1, booksubjectentomology, bookyear1912
