. Elements of ecology. Ecology. 312 Relations within the Species Active Locomotion Groups of the same species brought about by the active locomotion of the individuals may arise (1) from the guidance of the organisms towards the same area by oriented responses to inanimate features of the environment or (2) from the attraction of the organisms to others of their own kind. The formation of groups by active locomo- tion is, of course, found most frequently in the animal kingdom, but certain motile algae and the swarm spores of aquatic plants also exhibit this behavior. Common Orientation. If the
. Elements of ecology. Ecology. 312 Relations within the Species Active Locomotion Groups of the same species brought about by the active locomotion of the individuals may arise (1) from the guidance of the organisms towards the same area by oriented responses to inanimate features of the environment or (2) from the attraction of the organisms to others of their own kind. The formation of groups by active locomo- tion is, of course, found most frequently in the animal kingdom, but certain motile algae and the swarm spores of aquatic plants also exhibit this behavior. Common Orientation. If the individuals of a species react in the same way to some physical stimulus in the environment, their locomo- tion will bring them to the same locality with the result that an aggre- gation will be formed. A familiar example is the clustering of insects about a source of light at night as a result of their positive phototaxis, or the attraction of fish and invertebrate animals to a torch held over the water (Maeda, 1951). Since land isopods, such as the wood louse, move more slowly, or stop creeping entirely, under moist con- ditions they tend to collect in damp places. A dead fish on the shore or a dead deer in the forest acts as a lodestone to which a large num-. FiG. Aggregation of mud snails (Nassa obsoleta) exposed at low tide in Barnstable Harbor, 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 Clarke, George L. (George Leonard), 1905-. New York, Wiley
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Keywords: ., bookcentury1900, bookpublishernewyorkwiley, booksubjectecology
