Minot.] 56 » [October 26, 



indicate that the flight of the insect will be powerful and zig-zag. 

 The shape of the wing also exerts great influence ; e.g., a shoul- 

 dered costa adds strength to the wings and therefore to the flight; 1 

 or again, if the wings are very broad, the insect finds difficulty in 

 moving them, and the flight becomes slow and unsteady. The abdo- 

 men is used as a rudder. It is by means of this that dragon-flies can 

 turn so quickly. It may be well to mention here that all insects 

 turn, during flight, in one of two ways : first, as in the case of the 

 butterflies, by making a decided angle, the result being a zig-zag 

 course ; second, as in the dragon-flies, by making a curve, the course 

 through the air becoming a series of curves, each of which is tangent 

 to the preceding one. Numerous examples in confirmation of my 

 views might be adduced. 



The position of butterflies when at rest, I have studied in some 

 detail, and have arrived at some interesting results. A great variety 

 is found in their postures by day, but they are all different from those 

 which are assumed by night, which are almost exactly the same for 

 every individual of the same species. 



Having often been asked where insects spend the night, I selected 

 two of our commonest species, Colias Philodice Godt, and Pieris rapce 

 Schrank, and watched them for a great many evenings. A little be- 

 fore sundown they begin to alight in the grass very frequently ; as it 

 grows later they become more and more inactive, until finally they 

 will allow themselves to be trodden upon, pinned, and handled in any 

 way. ■ Before the twilight is ended they creep down, or descend in 

 some manner, I know not how, to the very roots of the stalk or blade 

 of grass they have selected for their resting place.. They always 

 choose a perpendicular stalk. The wings are raised over the back, 

 with the outer edges pressed together. The antennas are kept nearly 

 perpendicular to the axis of the body and are almost concealed be- 

 tween the front edges of the fore- wings. 



Mr. F. G. Sanborn exhibited specimens of Lepidoptera from 

 California and Neuroptera and Geometridae, presented by Dr. 

 G. F. Waters ; also insects purchased of G.. W. Belfrage, of 

 Texas, and a collection made by Prof. A. S. Bickmore, in 

 Southern Asia. 



1 Wallace, Contrib. Nat. Selec, p. 179, also bas noticed tbis fact. 



