A REPORT OF THE NEUROLOGICAL SEMINAR OF THE 

 ■ MARINE BIOLOGICAL LABORATORY, WOOD'S HOLL, 

 MASS., FOR THE SEASON OF 1899. 



By A. D. Morrill, 



A new and interesting feature of the fourth annual session of the 

 seminar was the reports on experimental psychology of animals by Dr. 

 Thorndike, who reported the results of his experiments with fishes, 

 and by Mr. Yerkes, who reported on similar work with turtles. Both 

 of these researches were undertaken to determine the associative power 

 of animals and the investigation is to be extended to all the groups 

 suitable for this method of study. 



Dr. Locy reported the results obtained in his laboratory by Dr. 

 Chas. Hill in the study of the metamerism of the head of living chick 

 and trout embryos. The great care with which the work was done and 

 the careful study of consecutive stages and repeated verification of the 

 work were considered by Dr. Locy as important, as the conclusions 

 strongly supported his own work. 



Dr. Metcalf reported on that part of his work on the Tunicata 

 bearing on the relation of the neural ganglion and the neural gland, in 

 development. The evidence obtained tended to support the position 

 that they arose from a common rudiment. Dr. Lefevre described the 

 origin of the neural ganglion in budding Perophora and Mr. Hunter 

 gave a demonstration of the ganglion cells in the neural gland of the 

 adult Molgula, by means of methylene blue. 



Dr. Lee summarized the evidence opposed to the existence of the 

 sense of hearing in Fishes. Dr. Lyon gave some very interesting dem- 

 onstrations of the compensatory movements of insects and some of the 

 vertebrates. Mr. Prentiss described the development and adult struc- 

 ture of the auditory, olfactory and tactile hairs of Palemonetes and the 

 innervation of the otocyst. The preparations of the otocyst demon- 

 strated in the clearest manner the relation of the nerves to the sensory 

 cells of the otocyst and to the brain. 



The gold chloride preparations of the nerves of the earthworm by 

 Professor Fling showed the relations of the main nerves of a segment 

 to each other and to the nerves of the adjoining segments, 



