110 THE ENTOMOLOGIST. 



tained at the several stations and for the several colours during 

 one experiment. The method also permits a very easy adjust- 

 ment of lights in their intensity, by raising or lowering the 

 wicks, and thus allows the observer to test strength of mere 

 illumination against attractiveness of colour as a hue for the 

 insects. The planting of the lights seems important. I started 

 by placing them in a row at long distances from each other. The 

 defect of this arrangement appeared to be that the brilliancy of 

 the first light, encountered by the insects coming upon it from 

 its side or portion of the row, interfered with the visitor's freedom 

 of choice as between that colour and another when the light from 

 the others reached it in a dim and imperfect manner. The 

 lanterns were then arranged in a square (four colours), whose 

 dimensions were determined by the intensity of the several 

 lights. The distance between the lanterns was such as to allow 

 the limital circle of illumination of each at first to touch, and 

 subsequently to intersect those of its neighbours. This distance 

 was reduced until [the separation between the lanterns was less 

 than the radius of the circles of light which each threw around 

 itself, the lights being of equal intensity. This proved unsatis- 

 factory, and having devised no means of exhibiting a number of 

 coloured lights so that the chances were equalised completely for 

 insects coming from all sides, to choose according to any consti- 

 tutional preference for one colour over another, I used only two 

 colours at a time. The arrangement might be found useful to 

 place four lanterns in two pairs, each pair of one colour, and in a 

 diamond pattern, so that each colour appears equalty prominent, 

 no matter from what side the dazzled insect may approach the 

 group. The apparent necessity for allowing the insect to choose 

 instantly between the colours before it reaches either arises from 

 the infatuation produced in the insects by the light, which once 

 reached seems to obliterate all capability in the creature to free 

 itself from its enticement, except in an irregular and accidental 

 manner. My experiments proved nothing except the absence of 

 any marked preference for certain colours over others, and the 

 almost invariably greater charm exerted by the white lantern, 

 which, on account of their translucency, appeared more brilliant 

 than the coloured lamps." 



Effect of Artificial Heat upon Hybernating- Lepi- 

 doptera.— On the 14th of January I was attending" a village 



