126 
Psyche 
[December 
In addition to the above morphological evidence, a close 
relationship of the Protoperlaria and the Neuroptera is in 
agreement with recent theoretical work on the origin of 
the larva, and the significance of the pupal stage. The 
nymphs of the Protoperlaria were described in detail by 
Carpenter (1935) ; they appear to have been similar to 
those of the Plecootera. Presumably, there was a large 
number of nymphal instars, as is the case in the Plecop- 
tera, some species of which have more than thirty. 
Bradley (1942) recognized the significance of the Proto- 
perlaria, suggesting them as possible ancestors of the 
Endopterygota because they are the most generalized known 
Neoptera, and because of some similarities in development 
of their close relatives, the Plecoptera, and of SiaHs. More 
recently. Sharov (1953, 1957) has developed a theory of 
the origin of holometabolous development from an insect 
with a large number of immature stadia, including both 
larval and nymphal stages, and with several imaginal in- 
stars. Of the living Neoptera, the Plecoptera, with their 
large number of immature stages, approach closest to this 
condition. 
The evidence described above appears sufficient to justify 
the statement that a close relationship probably exists be- 
tween the Protoperlaria and the Neuroptera; moreover, 
there is no known feature of the Protoperlaria which would 
prevent their being considered directly ancestral to the 
Endopterygota. 
Literature Cited 
Bradley, J. C. 
1939. A laboratory guide to the study of the evolution of the wings of 
insects. Daw, Illston, Ithaca, N. Y. 60 pp., S3 pi. 
1942. The origin and significance of metamorphosis and wings among 
insects. Proc. 8th Amer. Sci. Cong. 3:303-309. 
Carpenter, F. M. 
1935. The Lower Permian insects of Kansas. Part 7. The order Proto- 
perlaria. Proc. Amer. Acad. Art Sci. 70:103-146. 
Hanson, J. F. 
1946. Comparative morphology and taxonomy of the Capniidae (Ple- 
coptera). Amer. Mid. Nat. 35:193-249 
