SOME OF THE "LOWER ORDERS" 205 



Whether display, such as birds appear to delight in 

 ever takes place among the Lepidoptera seems doubtful 

 Nevertheless, something closely akin thereto seems to 

 have been found in fflrc case of certain species of Butter- 

 flies (fleliconius melpomene and H. rhea), which have been 

 seen dancing in the air like gnats, and when some of 

 them withdrew others took their places. Again, having 

 regard to the fact that birds, when alarmed or excited, 

 will perform the display which is more or less characteristic 

 of periods of sexual excitement, it is possible that the 

 position of alarm assumed by some of the Hawk Moths 

 may also be used in Courtship (Fig. i, Plate 31). But 

 we have no evidence on this point, and from the part 

 played by scent in the mating of Butterflies it seems 

 improbable that such displays take place. 



A serious attempt to test the Sexual Selection theory 

 by experiment — to test the extent, if any, of female choice 

 in mating — was made some years ago by Mayer, an 

 American naturalist, on the large Bombycid Moth {Cal- 

 losamia fromethed). This species exhibits striking dissimi- 

 larity between the sexes in regard to colour and 

 pattern. " The females," remarks Professor Kellog, " are 

 reddish brown in ground colour, while the males are 

 blackish, and in the two sexes the pattern is distinctly 

 different. . . ." Mayer took four hundred and forty- 

 nine pupae, in cocoons, of this moth and endeavoured to 

 discover, first of all, whether the males found the females 

 by sight or smell. Enclosing females in jars, some of which 

 were covered and some of which were uncovered, he 

 found that males paid no attention to females enclosed 

 in transparent jars so closed as to prevent the escape of 

 odours, while such as were enclosed in boxes or wrapped 

 in cotton-wool, so as to be invisible, but yet capable of 



