188 INVERTEBRATE PHYSIOLOGY 



evidence, predominantly from injection experiments but also, to a lesser 

 extent, from observations of chromatophoral behavior under other experi- 

 mental conditions, for sources of hormone outside the eyestalk, there is in- 

 sufficient evidence for the participation of these extra-eyestalk sources of 

 hormone in the normal physiology of color change. Panouse (1946, 1947) 

 has expressed some reservations as to the specificity of extracts of the 

 central nervous system in the activation of chromatophores. 



Carlisle, Dupont-Raabe, and Knowles (1955), using the methods of 

 paper electrophoresis, have undertaken separation of substances which 

 affect various components of the chromatophore system from extracts of 

 sinus glands and postcommissural organs of Leander. From extracts of 

 sinus glands and of postcommissural organs they obtained a substance A 

 which on injection caused concentration of the red and yellow pigments 

 of the large and the small chromatophores. Substance B, having different 

 migration properties and separable only from postcommissural organs, 

 upon injection, concentrated the large red chromatophores of the body 

 but expanded the red pigment of the small chromatophores of the body 

 and of the uropods. Other substances showing more marked electropho- 

 retic mobilities than A or B, but acting only on a single pigment, were 

 separable from postcommissural extracts when the latter were allowed to 

 remain a certain time at laboratory temperature (time and temperatures 

 not stated) ; the concentration of A and B in these extracts was diminished. 

 It is also reported that fresh extracts of the X-organ have no effect on the 

 chromatophores, but that the same extracts after boiling cause concentra- 

 tion of the dark pigments. These experiments indicate the possibility of 

 substances which by various treatments can be altered or broken down 

 into chromatophorotropically active components. 



Reproductive Systems 



The question of the existence of sex hormones in crustaceans which 

 maintain secondary sex characters has been under discussion by zoologists 

 for many years. The basis for this discussion has been the observable 

 change in the secondary sex characters of a number of species, either asso- 

 ciated with parasitic castration or induced experimentally by x-ray or 

 radium irradiation which destroyed the gonads. This subject has been 

 reviewed by a number of the authors mentioned in the introductory sec- 

 tion ; there seems to be general agreement that evidence for the secretion 

 of hormones from the gonads to maintain secondary sex characters is not 

 completely satisfactory. 



An attempt at experimental approach to this problem along the lines of 

 conventional endocrine surgery by Takewaki and Nakamura (1944) has 

 not been particularly fruitful in presenting evidence in favor of secretion 



