November 1S91.] 



PSYCHE. 



181 



one remarkable fact about this occurrence 

 was that these insects occupied a limited belt 

 in the centre of the valley, and did not ex- 

 tend to the elevated portions of the town on 

 either side. There were no insects about the 

 electric lights on the hillsides, and farther 

 down in the valley the lights were fre- 

 quented only by Lepidoptera. Where the 

 small insects were most abundant the Lepi- 

 doptera were wanting. Probably the small 

 insects drove them away. Looking from the 

 hillsides a cloudy phosphorescence was seen to 

 extend over the city in an irregular sheet, 

 with here and there patches and protuber- 

 ances rising high above the common mass. 

 Comparing the position of this cloud at 

 different times from seven until ten o'clock, 

 it was evident that the centres of maximum 

 density were moving northward, i. e., in the 

 same direction that the insects moved in the 

 early part of the evening. There was no 

 perceptible moisture in the air so that this 

 cloud could not be attributed to mist. It must 

 have been caused by the reflection of the 

 city lights upon the glossy wings of these 

 insects. 



Prof. D. A. Saunders tells me that a very 

 similar cloud passed over Alfred Centre, a 

 village about twelve miles southwest of Horn- 

 ellsville, on the evening of August 16. The 

 insects in this case were flying ants with de- 

 ciduous wings, so that, after the cloud had 

 passed, their wings were found very abund- 

 antly scattered over the ground. This cloud 

 made its appearance about sunset and had 

 passed over by dark. It came from a steep 

 hill overlooking the town and swept across 

 the town in a narrow belt, leaving the upper 

 and lower parts unmolested. He has ob- 

 served other clouds during the year in Flor- 

 ida, and says the inhabitants there are quite 

 familar with them. A rather remarkable 

 cloud of this kind was particularly observed 

 by him in the month of May at Sisco, Fla. 

 The insects on this occasion were large, and 

 had very glossy wings. The cloud began 

 about eisrht o'clock in the morning and lasted 



for half an hour. They seemed to rise 

 from a flat meadow densely overgrown with 

 grass. They ascended to an altitude of about 

 twenty feet, and continued the rest of their 

 course in a horizontal direction. The cloud 

 seems to have been confined chiefly to a 

 twenty-acre lot and did not pass to adjacent 

 parts. It was a warm, bright day, and the 

 reflection of light upon their wings gave the 

 cloud a striking resemblance to a snowstorm. 

 Their wings were deciduous, and neighbor- 

 ing pools were pretty much covered with 

 them. J. Lawton Williams. 



Notes. — The Royal Society of New South 

 Wales offers a prize of the Society's medal 

 and £25 for the best essay containing the re- 

 sults of original research on the injuries 

 occasioned by insect pests upon introduced 

 trees, the essay to be sent in before May 1, 

 1893. The competition is in no way con- 

 fined to residents in Australia, but is open 

 without restriction to all. 



In Nature Notes for August Mr. R. T. 

 Lewis, on the authority of a correspondent 

 in whose trustworthiness he has entire confi- 

 dence, gives a curious account of the appre- 

 ciation with which the song of the Cicada is 

 heard by insects other than those of its own 

 genus. The correspondent has frequently 

 observed in Natal that when the Cicada is 

 singing at its loudest, in the hottest portion 

 of the day, it is attended by a number of 

 other insects with lovely, gauze-like, irides- 

 cent wings, whose demeanour has left no 

 doubt on his mind that the music is the at- 

 traction. The Cicada, when singing, usually 

 stations itself upon the trunk of a tree with 

 its head uppermost, and the insects in ques- 

 tion, to the number sometimes of fifteen or 

 sixteen, form themselves into a rough semi- 

 circle at a short distance around its head. 

 During a performance one of the insects was 

 observed occasionally to approach the Cicada 

 and to touch it upon its front leg or antennae, 

 which proceeding was resented by a vigorous 

 stroke of the foot by the Cicada, without, 



