. Ecological animal geography; an authorized, rewritten edition based on Tiergeographie auf ockologischer grundlage . Fig. 3.—Outer branch of the first abdominal appendage of the land isopod Armadillidium nasutum, with much divided respiratory cavity. After Herold. covering for the remainder of the skin. In terrestrial vertebrates the number of layers of cells is increased, and the horny stratum, still single in the amphibians, is formed of more numerous layers of small cells. Protection against evaporation is thus based on structures al- ready available. Complete transition to an air-breathin
. Ecological animal geography; an authorized, rewritten edition based on Tiergeographie auf ockologischer grundlage . Fig. 3.—Outer branch of the first abdominal appendage of the land isopod Armadillidium nasutum, with much divided respiratory cavity. After Herold. covering for the remainder of the skin. In terrestrial vertebrates the number of layers of cells is increased, and the horny stratum, still single in the amphibians, is formed of more numerous layers of small cells. Protection against evaporation is thus based on structures al- ready available. Complete transition to an air-breathing existence became possible to the vertebrates, as to the invertebrates, by means of changes in the breathing apparatus. The gills of fishes, not unlike those of the higher Crustacea, afford a sufficient surface only in the water, as their branches cohere in the air. Of the various types of air-breathing or- gans developed among the fishes, lungs proved most successful. These originate as a sac-like evagination of the anterior part of the alimen- tary canal, just posterior to the hindmost pair of gill clefts.
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Keywords: ., bookcentury1900, bookcollectionbiodive, booksubjectanimalecology
