June, 1919 Bulletin of the Brooklyn Entomological Society 101 
modified in adaptation to their own environmental conditions, 
we must not lose sight of the fact that larvae may not exhibit 
later-developed, interpolated conditions in all their features of 
habit and structure, since in some respects the larve may be 
much more primitive than the adults, and present some char- 
acters of _considerable phylogenetic importance. Thus the head 
and mouth parts of some larval Lepidoptera are much more 
primitive than those of the adults, the thoracic sclerites of larval 
Neuroptera may be much more like those of the Apterygota than 
the sclerites of the adults are, the long segmented cerci of the 
larvee of certain carabid Coleoptera are much more primitive than 
the corresponding parts of the adult, and many similar features 
could be cited in this connection. In the lower forms, such as 
the Ephemerida, the mouthparts are frequently more like those 
of the Apterygota or Crustacea than the mouthparts of the adult 
are, and in the Plecoptera, I find that the head, thoracic sclerites 
and other parts, are more like those of the ancestral apterygotan 
type found in the Lepismide, than is true of the adult struc- 
tures. This brings up the question as to whether the primitive 
types of larve, with their membranous body wall, with their more 
primitive type of sclerites, head, mouthparts, legs, and abdominal 
structures, etc., may not in some instances represent the ancestral 
condition more nearly than the adults do. In some cases, I am 
inclined to think that this is true, although in other cases, it is 
very evident that the larve have become far more specialized 
than the adults, and have added many interpolated conditions in 
adaptation to their own peculiar environmental conditions. 
These features as well as those discussed above, must be taken 
into consideration in attempting to account for the origin of 
complete metamorphosis among insects, and I think that there 
are too many factors involved in its development, to attempt to 
offer any one explanation for the origin of holometabolism— 
which may have developed more or less independently in several 
groups of insects. 
PAPILIO CRESPHONTES, VAR. MAXWELLI FRANCK. 
_The type of this species is a male in the Barnes collection ; the 
type locality, St. Petersburg, Fla. Gro. FRANCK. 
