Hormones in the Crustacea Their Sources and Activities (Concluded)

Abstract

A molt- and consequently an inhibiting hormone have been demonstrated. Eyestalk removal, sinus gland extirpation and implantation, indicate that this gland possesses a favorable action upon viability. From the inj. of an extract of the ganglia together with the demonstration of a variation in the quantity of active principle in them following normally induced changes in chromatophores, it is established that the ganglia of Crago and Palaemonetes produce a chromatophoric hormone with physiological effects antagonistic to a sinus gland principle upon certain melano-phores and erythrophores. All of the principal central nervous organs of Crustacea yield a chromatophorically active substance. Parasitic castration of [male] crustaceans and a correlation between seasonal testis activity and the differentiation of secondary sexual characters indicate that a [male] sex hormone is produced in the testis. Destruction of ovaries by radiation likewise suggest that a [female] hormone is liberated by the ovaries.