The Insect World: Being a Popular Account of the Orders of Insects

Nonfiction, Religion & Spirituality, New Age, History, Fiction & Literature
Cover of the book The Insect World: Being a Popular Account of the Orders of Insects by Louis Figuier, Library of Alexandria
View on Amazon View on AbeBooks View on Kobo View on B.Depository View on eBay View on Walmart
Author: Louis Figuier ISBN: 9781465611376
Publisher: Library of Alexandria Publication: March 8, 2015
Imprint: Language: English
Author: Louis Figuier
ISBN: 9781465611376
Publisher: Library of Alexandria
Publication: March 8, 2015
Imprint:
Language: English
"Each facette, with its lens and nervous filament, separated from those surrounding them by the pigment in which they are enclosed, form an isolated apparatus, impenetrable to all rays of light, except those which fall perpendicularly on the centre of the facette, which alone is devoid of pigment. All rays falling obliquely are absorbed by that pigment which surrounds the gelatinous cone. It results partly from this, and partly from the immobility of the eye, that the field of vision of each facette is very limited, and that there are as many objects reflected on the optic filaments as there are corneæ. The extent, then, of the field of vision will be determined, not by the diameter of these last, but by the diameter of the entire eye, and will be in proportion to its size and convexity. But whatever may be the size of the eyes, like their fields of vision, they are independent of each other; there is always a space, greater or less, between them; and the insect cannot see objects in front of this space without turning its head. What a peculiar sensation must result from the multiplicity of images on the optic filaments! This is not more easily explained than that which happens with animals which, having two eyes, see only one image; and probably the same is the case with insects. But these eyes usually look in opposite directions, and should see two images, as in the chameleon, whose eyes move independently of each other. The clearness and length of vision will depend, continues M. Müller, on the diameter of the sphere of which the entire eye forms a segment, on the number and size of the facettes, and the length of the cones or lenses. The larger each facette, taken separately, and the more brilliant the pigment placed between the lenses, the more distinct will be the image of objects at a distance, and the less distinct that of objects near. With the latter the luminous rays diverge considerably; while those from the former are more parallel. In the first case, in traversing the pigment, they impinge obliquely on the crystalline, and consequently confuse the vision; in the second, they fall more perpendicularly on each facette.
View on Amazon View on AbeBooks View on Kobo View on B.Depository View on eBay View on Walmart
"Each facette, with its lens and nervous filament, separated from those surrounding them by the pigment in which they are enclosed, form an isolated apparatus, impenetrable to all rays of light, except those which fall perpendicularly on the centre of the facette, which alone is devoid of pigment. All rays falling obliquely are absorbed by that pigment which surrounds the gelatinous cone. It results partly from this, and partly from the immobility of the eye, that the field of vision of each facette is very limited, and that there are as many objects reflected on the optic filaments as there are corneæ. The extent, then, of the field of vision will be determined, not by the diameter of these last, but by the diameter of the entire eye, and will be in proportion to its size and convexity. But whatever may be the size of the eyes, like their fields of vision, they are independent of each other; there is always a space, greater or less, between them; and the insect cannot see objects in front of this space without turning its head. What a peculiar sensation must result from the multiplicity of images on the optic filaments! This is not more easily explained than that which happens with animals which, having two eyes, see only one image; and probably the same is the case with insects. But these eyes usually look in opposite directions, and should see two images, as in the chameleon, whose eyes move independently of each other. The clearness and length of vision will depend, continues M. Müller, on the diameter of the sphere of which the entire eye forms a segment, on the number and size of the facettes, and the length of the cones or lenses. The larger each facette, taken separately, and the more brilliant the pigment placed between the lenses, the more distinct will be the image of objects at a distance, and the less distinct that of objects near. With the latter the luminous rays diverge considerably; while those from the former are more parallel. In the first case, in traversing the pigment, they impinge obliquely on the crystalline, and consequently confuse the vision; in the second, they fall more perpendicularly on each facette.

More books from Library of Alexandria

Cover of the book A Hundred and Sixty Books by Washington Authors: Some Other Writers Who Are Contributors to Periodical Literature, Lines Worth Knowing by Heart by Louis Figuier
Cover of the book Germinal by Louis Figuier
Cover of the book The Canadian brothers, or The Prophecy Fulfilled a Tale of The Late American War, Complete by Louis Figuier
Cover of the book The Grey Wig: Stories and Novelettes by Louis Figuier
Cover of the book Tempest-Driven: A Romance (Complete) by Louis Figuier
Cover of the book There was a King in Egypt by Louis Figuier
Cover of the book The Beasts' Confession by Louis Figuier
Cover of the book When Wilderness was King: A Tale of the Illinois Country by Louis Figuier
Cover of the book The Torn Bible or Hubert's Best Friend by Louis Figuier
Cover of the book Knowledge Is Power: A View of the Productive Forces of Modern Society and the Results of Labor, Capital and Skill by Louis Figuier
Cover of the book Under the Great Bear by Louis Figuier
Cover of the book Woman and Artist by Louis Figuier
Cover of the book The Adventurous Life of a Versatile Artist: Houdini by Louis Figuier
Cover of the book Cœur de panthère by Louis Figuier
Cover of the book Six Discourses on the Miracles of our Saviour and Defences of his Discourses by Louis Figuier
We use our own "cookies" and third party cookies to improve services and to see statistical information. By using this website, you agree to our Privacy Policy