. The life of inland waters; an elementary text book of fresh-water biology for American students. Freshwater biology. 174 Aquatic Organisms Fig. 82. Dero, in its case made of floating seeds. Aquatic earth-worms, more like the well-known terrestrial species, burrow deeply into the mud of the pond bottom. Other worms occur in the water in great variety; we have mentioned only a few of the commonest, and those most frequently seen. There are many parasitic worms that appear in the water for only a brief period of their lives: hair-worms {Gordius, etc.), which are freed from the bodies of insects
. The life of inland waters; an elementary text book of fresh-water biology for American students. Freshwater biology. 174 Aquatic Organisms Fig. 82. Dero, in its case made of floating seeds. Aquatic earth-worms, more like the well-known terrestrial species, burrow deeply into the mud of the pond bottom. Other worms occur in the water in great variety; we have mentioned only a few of the commonest, and those most frequently seen. There are many parasitic worms that appear in the water for only a brief period of their lives: hair-worms {Gordius, etc.), which are freed from the bodies of insects and other animals in which they have developed; these often appear in watering troughs and were once widely believed to have generated from horse-hairs fallen in the water. There are larval stages {Cercaria) of Cestodes and others, found living in the water for only a brief interval of passage from one host animal to ano- ther. There are les- ser groups also like the Nemertine worms, sparingly represented in fresh- water; for informa- tion concerning these the reader is referred to the larger textbooks of Fig. 83. Tubifex in the bottom 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 Needham, James G. (James George), 1868-1956; Lloyd, John Thomas, 1884- joint author. Ithaca,N. Y. , The Comstock Publishing Company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1915
