LEPIDOPTERA — NOCTUIDyE. 



49 



the bend at "4" an interesting case was noted. Three moths quite near 

 each other did not head from the direction of the entrance, but at a 

 considerable angle from it. The light from the entrance struck the 

 east side of the wall at "4" at the proper angle and so strongly that 

 the reflected rays served as the principal source of light for a region on 

 the roof, and it was in this area that these moths were located and to 

 this source of light that they had oriented themselves. It must be said, 

 however, that some of the moths upon the wall, and occasionally one 

 upon the roof, are not oriented with their heads from the source of 

 light. Not all the individuals orient themselves immediately upon 

 arrival, but in a few days nearly all are oriented. Otherwise they do 

 not orient themselves at all. I turned a number of individuals so that 

 their heads were toward the source of light or at right angles to it. 

 The position of each was indicated by arrows on the roof or wall and 

 noted so that the same individual could be observed on another trip and 

 its change of position, if any, noted. In the following table are given 

 the results of this experiment. 



Table showing results of experiments as to orientation of Scoliopteryx libatrix to light. 



No. of 

 Indi- 

 vidual. 



a, b, c, 

 d, e. 



2 



8 



9 



10 



H 



12 



Position of head 

 with regard to light 



[Toward 



From 



At right angles 



Position of moth 



changed or marked 



as found. 



Disturbed 



Undisturbed. 

 Disturbed 



Oct. 28, 

 1!K)4. 



Nov. 11, 

 1904. 



Marked . . . 



....do 



Toward 



From light spot on 

 east wall. 



Slightly toward do. 



From light spot on do. 



opposite wall. . . j 



M right angles Disturbed 



From i Undisturbed. 



Toward i Disturbed 



do Undisturbed, 



Found at rightj Disturbed 



angles, turned 



180° and left at 



right angles. 



Undisturbed | Marked 



— do I do 



....do 



All gone. 



Marked. . 

 Marked . . 



Unmoved. 



...do 



Dec. 9, 

 1904. 



Unmoved.. 



Moved 4 

 inches and 

 from light. 



Unmoved. . 



do 



Marked 



Dec. 21, 

 1904. 



Marked... 



do i 



Unmoved. 



Marked 



do 



do 



Unmoved. 

 Gone. 



Unmoved. 

 Do. 

 Do. 



Do. 

 Do. 



Gone. 



Unmoved. 



Gone. 



Marked. 



Marked. 



No. of 

 indi- 

 vidual. 



Jan. i9, 



1905. 



1 

 3 

 4 



S 



6 



7 



9 

 11 

 12 



Jan. 28, 

 1905. 



Feb. 17, 



1905. 



Unmoved Unmoved Unmoved. 



do do do 



do do do 



do do ' do 



.do. 

 .do. 



.do. 

 .do. 

 .do. 



.do. 

 .do. 



.do. 

 .do. 

 .do. 



.do. 

 .do. 



.do. 

 .do. 

 .do. 



Mar. 4, 



1905. 



Unmoved. 



do 



do 



do 



.do. 

 .do. 



.do. 

 .do. 

 .do. 



Apr. 8., 

 1905. 



Apr. 29, 

 1906. 



Gone 



Unmoved. 



Gone 



do 



.do. 

 .do. 



....do 



....do 



Unmoved.. 



Gone. 



Gone. 



