722 



SCIENCE 



[N. S. Vol. XXV. No. 645 



Vice-president and Chairman — E. B. Wilson, 

 New York. 



Becretary — 0. Judson Herrick, Granville, Ohio. 



Mernber of Council — ^Herbert Osbom, Columbus. 



Member of General Committee — E. L. Eice, 

 Delaware, Ohio. 



Sectional Committee — E. B. Wilson, E. G. Conk- 

 lin, O. Judson Herrick, H. B. Ward (one year), 

 Frank Smith (two years), W. E. Ritter (three 

 years), A. M. Bleile (four years), A. L. Tread- 

 well (five years). 



AMERICAN SOCIETY OF ZOOLOGISTS 



The fourth annual meeting of the East- 

 ern Branch and the seventeenth annual 

 meeting of the society since its establish- 

 ment as the American Morphological So- 

 ciety elected the following officers for 1907 : 



President — Charles B. Davenport. 



Vice-president — F. H. Herrick. 



Secretary-Treasurer — H. E. Crampton. 



Member of Executive Committee (to serve three 

 years) — W. R. Coe. 



Eleven persons were elected to member- 

 ship, making the total membership of the 

 Eastern Branch 135. A grant of $125 was 

 voted toward the expenses of the Interna- 

 tional Zoological Congress to be held in this 

 country next August. 



Professor Crampton tendered his resig- 

 nation as secretary-treasurer, and after ad- 

 journment of the session C. Judson Herrick 

 was appointed by the executive committee 

 to fiU the vacancy. 



JOINT PROGRAM 



The Functions of the Nervous System of 

 the Razor-shell Clam: G. A. Drew, Uni- 

 versity of Maine. 



On the Sense of Sight of Spiders: A. Pe- 



TRUNKEViTCH, Indiana University. 

 The Sense of Vision in the Dancing Mouse: 

 Egbert M. Yereiis, Harvard University. 

 That brightness vision is fairly weU de- 

 veloped in the dancer is shown by its ability 

 to discriminate blacks, grays and whites. 

 Color vision is extremely poor. There is 

 some indication of the discrimination of 



red and green and of red and blue, but 

 none whatever of blue and green. AU my 

 experimental tests as well as my observa- 

 tions of the habits of the mouse support the 

 conclusion that such visual guidance as is 

 received results from stimulation by bright- 

 ness differences. There are many reasons 

 for believing that the red end of the spec- 

 trum is much lower in brightness value for 

 the mouse than for man. The general be- 

 havior of the dancer and the results of 

 form, brightness and color tests show that 

 vision ia not very important in the life of 

 the animal. 



An Experimental Study of the Image- 

 forming Powers of Various Types of 

 Eyes: Leon J. Cole, Ehode Island Agri- 

 cultural Experiment Station, Kingston, 

 E. I. 



The responses of certain phototropic ani- 

 mals to two areas of light of different size, 

 but of equal intensity, were used as criteria 

 in drawing inferences as to the image- 

 forming powers of their eyes. To one side 

 was a ground-glass, lighted from behind, 

 which gave an evenly illuminated area 41 

 cm. square. To the other side was prac- 

 tically a point of light; but at the position 

 midway between them, where the experi- 

 ments were performed, the intensities of 

 the two lights were equal. Eyeless forms 

 (the earthworm was used) turned practic- 

 ally an equal number of times toward each 

 light, showing no power of discriminating 

 between them. Animals with 'direction 

 eyes' were but little better in this respect 

 (e. g., Bipalium, Oniscus, larva of Tene- 

 hrio). On the other hand, animals with 

 weU-developed 'compound eyes' (Vanessa, 

 Banatra) and 'camera eyes' (frogs) dis- 

 criminated readily, positive animals turn- 

 ing much more often to the large light, and 

 negative animals more often to the small. 

 This discrimination was taken as evidence 

 of image-formation by the eyes. Frogs 



