776 



SCIENCE. 



[N. S. Vol. V. No. 124. 



the surf on sandy beaches it will be seen 

 that viviparity is a necessary condition of ex- 

 istence with these forms. A full series of 

 the eggs and embryos of Cymatogaster aggregatus 

 and the adults of this and five other species of 

 Embiotocidse were exhibited. Attention was 

 also called to a number of specimens of the 

 singular little blind fish {Typhlogohius calif or- 

 niensis, which lives in the burrows of Callianassa 

 under rocks at Point Loma, near San Diego. 

 William Morton Wheelee. 



new york academy of sciences — sub-section 

 of psychology and anthropology, 



APRIL 26, 1897. 



The Academy met with Professor Thomas R. 

 Price in the chair. The following papers were 

 presented: 'Mental Imagery,' by Mr. W. 

 Lay. The paper was a brief report of the 

 result of two years' study and research. Of one 

 hundred and twenty-five New York artists, the 

 speaker found but three or four who exhibited 

 the extraordinary degree of the power of visual- 

 izing which might be looked for in individuals 

 trained to observe things from a purely pic- 

 torial standpoint. One hundred and fifty col- 

 lege students gave the same result. The speaker 

 described the methods and gave the results of 

 his experiments on himself to determine in terms 

 of what sense the content of his own train of 

 thought was chiefly composed. He has studied 

 also the elements of mental imagery to be dis- 

 covered in language and the visual, auditory 

 and other imagery in poetry. 



'Visual After-images,' by Mr. S. I. Franz. 

 The speaker first described a typical after-image 

 and referred to the interest the phenomena had 

 aroused, as shown by the number of prominent 

 scientists that had discussed them. Their im- 

 portance was shown both for a correct theory 

 of color vision and epistemologically as con- 

 necting links between sensation and memory 

 and imagination. Experiments on the produc- 

 tion (i. e., the threshold) and on the duration 

 were then described, and curves showing the 

 results obtained were exhibited. The psychic 

 relationsof the different physical variables (viz. 

 time, area and intensity) were discussed. The 

 great individual variations, particularly in the 

 coloration, showed that the after-image is not 



simple but exceedingly complex, and that the 

 present theories to explain the phenomena are 

 inadequate. 



Livingston Farrand, 



Secretary pro tern. 



THE ACADEMY OF SCIENCES OF ST. LOUIS. 



At the meeting of the Academy of Science of 

 St. Louis, held on the evening of May 3, 1897, 

 21 persons present, Mr. H. Von Schrenk spoke 

 of the respiration of plants, with special refer- 

 ence to the modification of those growing with 

 their roots submerged in water. The lecture 

 was illustrated by a demonstration of the liber- 

 ation of carbon dioxide in respiration, from the 

 roots of an ordinary flowering plant and freshly 

 gathered fungi, and the more usual aerenchyma 

 structures were made clear by the use of lan- 

 tern slides. 



Professor F. E. Nipher described a simple 

 means of measuring the resistance of a tube to 

 the flow of a current of air, when compared 

 with an accepted standard, by the use of 

 a tubular device similar in principle to the 

 Wheatstone bridge, used in electrical instru- 

 ments ; the apparatus, in the present instance, 

 consisting of parallel tubes filled with air, con- 

 nected by a tubular bridge, in the middle of 

 which a drop of water was placed, so as to 

 change position with the variations in the flow 

 of air on the one hand or on the other. 



William Trelease, 



Secretary. 



NEW BOOKS. 



The Development of the Frog's Eggs; an Intro- 

 duction to Experimental Embryology. Thomas 

 Hunt Morgan. New York and London, 

 The Macmillan Company. 1897. Pp. x+192. 



Navahoe Legends, collected and translated by 

 Washington Matthews. Boston and New 

 York, Houghton, Mifflin & Co. 1897. Pp. 

 viii-F299. 



Introductory Course in Differential Equations. D. 

 A. Murray. New York, London and Bom- 

 bay, Longmans, Green & Co. 1897. Pp. 

 xv+234. 



The Science of Speech. Alexander Melville 

 Bell. Washington, D. C. , The Volta Bureau. 

 1897. Pp. 56. 



