576 SCIENCE PROGRESS 



Aug. 20, 1922 (" A Case of True Hermaphroditism in the 

 Fowl with Remarks upon Secondary Sex Characters "). The 

 bird was a Rhode Island Red fowl, nine years old, and possessed 

 an ovotestis and a testis both active. " The hermaphrodite 

 displayed external characters and behaviour of both sexes." 

 The ovotestis contained the so-called " interstitial " and 

 " luteal cells." The latter are considered by the writers to 

 be the endocrine cells of the ovary responsible for hen-feathering. 



H. Erhard has carried out investigations on the reaction 

 of some common Crustaceans to light (" Zur Kenntnis des 

 Lichtsinnes einiger niederer Krebse," Zool. Jahr., Bd. 39, 

 Heft I, 1922). Cyclops, Chydorus, and Diaptomus were found 

 to be positively phototropic. The reaction depends upon the 

 condition of adaptation. The sensitivity of the animals to 

 brightness discrimination is scarcely less than that of the 

 human eye. They follow in this respect the Weber Law. 

 Reaction to the spectral colours is similar to that of the human 

 eye with its " night vision," or the colour-blind eye. These 

 animals also react to ultraviolet light. 



L. T. Hogben and F. R. Winton have contributed a second 

 paper on " The Pigmentary Effector System," to the Proc. 

 R. S. (vol. xciv, No. B 658). This paper deals with an investi- 

 gation as to the existence of a nervous mechanism of pigment 

 control in the light of experiments carried out with frogs, 

 on the section and stimulation of nerves and the administra- 

 tion of drugs. With the exception of caffeine, the only reagents 

 found to induce melanophore contraction were those known to 

 excite peripheral sympathetic nerve endings, and apart from 

 pituitary extract, the reagent which induced expansion of the 

 melanophores must have paralysed all sympathetic nerve 

 endings. No unequivocal direct evidence has been advanced 

 to demonstrate a nervous control of these pigment responses. 

 The writers therefore conclude, " the possibility is indicated 

 that the synchronous colour changes of Amphibia in response 

 to normal environmental stimuli are determined mainly by 

 endocrine influences." 



After removing the parathyroid glands from the albino 

 rat, F. S. Hammett has found that there is a marked increase 

 in the size of the submaxillary glands. As the same result 

 is not attained after thyro-parathyroidectomy, he concludes 

 that " the cause of the enlargement is not attributable to any 

 local irritation produced by the operative procedure. It is 

 possible that the hypertrophy or hyperplasia is a response 

 to an increased functional activity induced by the increased 

 neural irritability resulting from the removal of the para- 

 thyroids " (" Studies of the Thyroid Apparatus, VI : The 

 Response of the Submaxillary Glands of the Albino Rat to 



