76 



SCIENCE 



[N. S. Vol. XXIX. No. 732 



When r.C.S. you claim, a3 is your rightful due — 

 The S alone is what they, grudging, give! 

 Be patient! Time is on your side. 

 Reason and justice will your cause defend. 

 Ignoble spite and arrogance of pride 

 Shall meet their retribution in the end! 



UNIVERSITY AND EDUCATIONAL NEWS 



Mr. George M. Laughlin, of Pittsburg, has 

 bequeathed, in addition to $125,000 to tlie hos- 

 pitals of the city, $100,000 to Washington and 

 Jefferson College. 



The authorities of University College, Bris- 

 tol, as part of the scheme to establish a Uni- 

 versity for the West of England, have pur- 

 chased the Blind Asylum and its lands, vchich 

 adjoin University College. 



In memory of the late Sir George Livesey, 

 it is proposed to establish a professorship of 

 fuel and gas engineering at Leeds University, 

 for -which purpose at least £10,000 will be col- 

 lected. 



Dr. F. W. Eurich has been appointed pro- 

 fessor of forensic medicine in the University 

 of Leeds. 



Dr. Max Eubner^ professor of hygiene at 

 Berlin, will succeed Professor W. Engelmann 

 as professor of physiology. 



As successors of Professor Haeckel, at Jena, 

 the faculty has proposed Professor Lang, of 

 Zurich, Professor Kiickenthal, of Breslau, or 

 Professor Platte, of Berlin. It is said that 

 Professor Platte will be selected by the ad- 

 ministration. 



DISCUSSION AND CORRESPONDENCE 



LIGHTS ATTRACTING INSECTS 



To THE Editor of Science: In the issue of 

 Science of December 4, 1908 (N. S., Vol. 

 XXVIIL, pp. 79Y, Y98), Mr. Owen Bryant 

 states certain observations and asks certain 

 questions regarding the reaction of insects to 

 lights from different sources. As to the rela- 

 tive efficiency in attracting insects of mercury 

 vapor lights, flaming arc lights using sodium 

 carbons, and ordinary arc lights, when all are 

 of the same area, I can give no information, 

 nor am I aware that accurate tests of this 

 nature have been made. In a general way, 

 however, it is probable that Mr. Bryant's view 



that the light of shorter wave-lengths has more 

 effect is correct, since it has long been known 

 that certain insects, such as ants, give little or 

 no response to red light. This is generally 

 true for the lower organisms, even including 

 Amoeiba. 



But Mr. Bryant has made the common mis- 

 take of considering only the intensity and 

 quality of the lights and not taking the area 

 into consideration. His observations are very 

 similar to those of Loeb,' who found that a 

 certain crepuscular moth (Sphinx euphorhice), 

 when liberated in a room lighted on the one 

 side by a window and on the other by a 

 kerosene lamp, always flew to the window 

 unless it was very close to the lamp when set 

 free. Parker'' made further experiments on 

 the same phenomenon in Vanessa, and I have 

 elsewhere published^ the results of experiments 

 on several species of insects and a number of 

 other animals, whose reactions were tested to 

 two lights of the same quality and equal in- 

 tensity, but of different area. The general 

 result was that positively phototropic animals 

 possessing image-forming eyes, such as the 

 butterflies and moths, reacted by going much 

 more often toward the larger light. This 

 would seem to explain the observations of Mr. 

 Bryant in the room, and might possibly apply 

 to some of the kinds of lamps he mentions. 

 At any rate, it shows the necessity of keep- 

 ing in mind the factor of the size of the 

 sources of illumination as well as the intensity 

 and quality of the light they give. In con- 

 sidering size the large globe (as in the case of 

 the arc light) and other parts or adjacent 

 surfaces that reflect light must be taken into 

 account. 



Leon J. Cole 



' Loeb, J., " Der Heliotropismus der Thiere und 

 seine Uebereinstimmung mit dem Heliotropismus 

 der Pflanzen," Wiirzburg, 1890, p. 47. 



' Parker, G. H., " The Phototropism of the 

 Mourning-cloak Butterfly, Vanessa antiopa Linn.," 

 Mark Anniversary Volume, No. 23, pp. 453-69, 

 pi. 33, 1903. 



' Cole, L. J., " An Experimental Study of the 

 Image-forming Powers of Various Types of Eyes," 

 Proo. Amer. Acad. Arts and Sci., Vol. 42, No. 16, 

 pp. 333-417, 1907. 



