Sex [electronic resource] . f its functions, namely, making glycogen(or animal starch) which is used in the ripening female the blood becomesprogressively charged with fat and lutein,and this might be described as the distinc-tively feminine condition of the blood. Nowthe roots of the Sacculina penetrating throughthe male crab affect the metabolism just asan ovary does in a female. They take up fatand stimulate the liver to make more. Theglycogenic function is depressed, for there isan absence of demand for glycogen, therebeing no growing or moulting after theSacculina has protruded
Sex [electronic resource] . f its functions, namely, making glycogen(or animal starch) which is used in the ripening female the blood becomesprogressively charged with fat and lutein,and this might be described as the distinc-tively feminine condition of the blood. Nowthe roots of the Sacculina penetrating throughthe male crab affect the metabolism just asan ovary does in a female. They take up fatand stimulate the liver to make more. Theglycogenic function is depressed, for there isan absence of demand for glycogen, therebeing no growing or moulting after theSacculina has protruded on the under sideof the crab (see Fig. 16). It has not beenshown that the males blood is actuallycharged with lutein and fat, but the liver isalways coloured with lutein, and so are the 86 SEX Sacculina roots, showing that a transferenceof these materials has occurred, perhaps sorapidly that their presence in the blood cannotbe detected. Smiths view is in general that the parasitealters the composition of the males blood to. Fig. 16.—Male crab Inachus with the sac-like parasite,Sa-cculina (S) protruding between the under surfacesof the abdomen and the cephalothorax. Forceps andabdomen modified towards female type. (After GeoffreySmith.) or towards a female condition, and that thisis naturally followed by the development offemale secondary characters, or by the regene-ration of an ovary instead of a testis fromthe indifferent germ-cells that remain at theend of infection. In short he would supple- THEORY OF SEX-DIMORPHISM 87 ment the r61e of hormones by recognising theimportance of metabolism-stimulation. Using the terminology of The Evolution ofSex, Geoffrey Smith says of the adaptiveregulation of the metabolism in the parasitisedmale crab that this adaptive regulationconsists in the production of at least a par-tially female condition of metabolism as op-posed to a wholly male condition, the femalecondition being preponderantly anabolic orconservative, as opposed to the kata
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