FROM EMBRYOLOGICAL DATA. 17 



nocturnal would be also once and for ever established. This seems very natural, as 

 soon as it has been shown that the caterpillar of the diurnal Lepidoptera already 

 ranks higher, on the whole, than that of the nocturnal ones. And this being the 

 case, we are naturally led to expect that the next stage in the metamorphosis 

 should bring the next stage of development higher also. 



These views might seem, at first, sustained by very slight evidence. But let us 

 now fnrther consider the perfect state of development of these different Lepidop- 

 tera, and we shall find, not only additional evidence of the view I have taken of 

 this subject, but perhaps still stronger reasons for adopting it. Here, again, I wish 

 to call attention anew and more emphatically to another point in the development 

 of Eudamus, and the diurnal Lepidoptera in general. 



The position of the wing of the perfect butterfly differs widely in its matured 

 condition from its position in the pupa, and to this point entomologists have paid 

 far too little attention, if they have at all noticed the fact. In all Sphinges and 

 Moths the upper surface of the wings is always turned sideways and upwards, the 

 wing being rolled downwards upon the sides of the larval body ; when hatched from 

 the pupa-skin the wings are spread horizontally, or more or less sloping doAvnwards, 

 in the same relation to the body which they had within the pupa, the lower surface 

 of the wings resting upon the body, the upper being turned outwards. There are 

 various modifications in the disposition of these parts : the wings in some sloping 

 more sideways, and still encircling the body as in the pupa; in others being spread 

 flat and horizontally to a greater or less extent, the upper wing, however, overlap- 

 ping the lower wings very extensively, and almost always covering them wholly in 

 the state of rest, as is the case within the pupa-skin. 



Such, however, is not the position of the wings in diurnal Lepidoptera. In the 

 mature stage of growth they are raised above the body, the upper surface being 

 turned upwards and inwards, and never turning outwards or sloping dowuAvards ; 

 the upper wings spreading in a manner which leaves the under wings uncovered, 

 and neither pair of wings bending downwards, to encircle more or less the body, as 

 is seen among so many of the moths. 



But this disposition of the wings, this character of the perfect butterfly, this mode 

 of carrying their organs of locomotion when at rest, or in activity, is peculiar to the 

 Papilionidse only in their perfect state. In their pupa condition the wings are 

 placed precisely as in all other Lepidoptera. They are bent downwards, the upper 

 wings covering the lower ones, and the upper surface of the latter being turned 

 sideways. And as no one can doubt that this change in the position and characters 

 of the wings in the diurnal Lepidoptera is something which grows out of a con- 

 dition common to all, it is as plain as any other embryological evidence can be, that 

 the development of diurnal Lepidoptera goes beyond what is observed in Sphinges 

 and Phalsenae. Assigning, therefore, to diurnal Lepidoptera, upon mature compar- 

 ison, a decidedly suj^erior position in their order, the Skippers, Hesperidse, would 

 rank next, from the circumstance that they raise the anterior wings only, and stretch 

 the lower ones more or less horizontally. 



My special knowledge of Lepidoptera is not at present sufficient to carry this 



VOL. II. ART. 6. — 3 



