Title: Animal activities : a first book in zoölogy
Identifier: animalactivities00fren (find matches)
Year: 1903 (1900s)
Authors: French, Nathaniel S. (Nathaniel Stowers), 1854-
Subjects: Zoology; Animal behavior
Publisher: New York ; London : Longmans, Green, and Co.
Contributing Library: Internet Archive
Digitizing Sponsor: Internet Archive

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Text Appearing Before Image:
78 ANIMAL ACTIVITIES. Breathing of a Dragon-fly Nymph. An insect living in the water must breathe, and it is interesting to observe how insects which have chosen an aquatic life have adapted their breathing-organs to the medium in which they live. The dragon-fly larva does not trouble himself to come to the surface for air, but simply takes his oxygen from the air dissolved in the water. The spiracles which would allow water as well as air to enter the breathing-tubes are closed and covered by the hard exo-skeleton, but the tracheae or breath-
Text Appearing After Image:
FiG. 69.—The Imago of a Dragon-fly. ing-tubes, like those in the grasshopper, convey the air throughout the body. To get the air, the water is dra\\ n in through the anal opening, where it comes in contact with some modified air-passages which have somewhat the function of gills. In these air-passages the carbon dioxide and other impurities await the opportunity to pass by osmosis to the water, while the oxygen penetrates through the membranes into the breathing-tubes. If a fine stream of bright-colored liquid be put near a nymph by means of a small pipette the currents produced by the breathing may be seen.

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