. Animal hormones; a comparative survey. Hormones. 242 METABOLIC HORMONES causes a fourfold rise in blood calcium lasting about 5 days (Fig. 5-26). The effect has been obtained in old crabs which would not have moulted again (terminal anecdysis, Carlisle, 1957), and is followed by moulting within a few weeks, if injections are repeated. The same hormone appears to be responsible for moulting and for Ca increase. This accounts for the earlier observations on many decapods, such as Crangon, Panidirus, Astacus, Carcinus and Uca^ that removal of the eyestalks increases the blood calcium; for the e
. Animal hormones; a comparative survey. Hormones. 242 METABOLIC HORMONES causes a fourfold rise in blood calcium lasting about 5 days (Fig. 5-26). The effect has been obtained in old crabs which would not have moulted again (terminal anecdysis, Carlisle, 1957), and is followed by moulting within a few weeks, if injections are repeated. The same hormone appears to be responsible for moulting and for Ca increase. This accounts for the earlier observations on many decapods, such as Crangon, Panidirus, Astacus, Carcinus and Uca^ that removal of the eyestalks increases the blood calcium; for the eyestalks contain a hormone which inhibits the action of the Y-organ that lies within the head capsule. Increased blood calcium leads to the formation of calcareous gastroliths, which serve as stores of calcium and normally show a diurnal rhythm in their rate. Doys ofter injection Fig. 5-26. Effects of an injection of an extract of Y-organ of the crab, Carcinusf on the level of the blood calcium (ordinates) in the same species, during the succeeding 5 days (abscissae). Black circles show the effect on specimens in terminal anecdysis, when they no longer moult naturally and do not secrete any hormone from their own Y-organ. Open circles (below) show the lack of effect of an extract of leg nerve on similar specimens (from Carlisle, 1957).. 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 Jenkin, Penelope M. Oxford, New York, Pergamon Press
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Keywords: ., bookcentury1900, bookcollectionbiodiversity, booksubjecthormones
