434 Journal of Comparative Neurology and Psychology. 



Mills, C. K. The Physiological Areas and Centers of the Cerebral Cortex of 

 Man, with New Diagrammatic Schemes. Univ. of Penna. Medical Bulle- 

 tin, XVII, 3, pp. 90-98, May, 1904. 

 The history and tlieor}' of cortical localization are briefly re- 

 viewed and the new features of the author's diagrams commented upon. 



c. J. H. 



McCarthy, D. J- The Formation of Bone Tissue within the Brain Substance. 

 A Contribution to the Inclusion Theory of Tumor Formation. Univ. of 

 Penna. Medical Bulletin, XVII, 3, pp. 120-121, May, 1904. 



Report of a small tumor containing true bone tissue which ap- 

 peared in the cerebral hemisphere of a young cat subsequent to an ex- 

 perimental lesion. c. j. h. 



Piper, H. Das elektromotorische Verhalten der Retina bei Eledone moschata. 

 Archiv fur Anato»iie und Physiologie, pp. 453-^74, 1904. 



The author starts out from the observation that water, and especi- 

 ally the water of the Mediterranean Ocean, strongly absorbs red and 

 yellow rays of light so that the sunlight which reaches moderate depths 

 below the surface is strongly tinged with blue and green. Him.stedt 

 and Nagjel had discovered' in 1901 that the action currents of the 

 frog's retina are stronger for intense yellow light (natrium) than for any 

 other intense colored stimulations which they applied. Now the yel- 

 low portion of the solar spectrum as measured bolometrically has a 

 greater energy than any other part, so that these authors referred the 

 greater action currents for yellow light to an economical adaptation of 

 nature, whereby the light most predominant in nature has also the 

 greatest stimulation value. The human eye receives the most intense 

 sensation from the yellow part of the spectrum, so that they further 

 concluded that the action currents of the retina are a fair measure of 

 the intensity of the sensation being carried to the brain. And in con- 

 firmation of this they actually discovered that a frog's retina when 

 adapted to "rod vision" before being removed, would then give greater 

 action currents for blue-yellow light than for the yellow light to which 

 the unadapted retina l)est responds ; just as the human adapted eye 

 sees the blue-yellow part of the spectrum as brightest (Purkixje phe- 

 nomenon). 



Now Dr. Piper inquires whether animals living some distance be- 

 low the level of the sea will give the strongest retinal action currents 

 for that color of light to which they are most exposed ; and more par- 

 ticularly, whether animals living in the depths of the Mediterranean 

 Ocean will have the strongest retinal currents for that blue light by 

 which they are always surrounded. In fact, the author finds this to 



