1966 ] Carpenter — Protorthoptera and Orthoptera 47 
In the present state of our knowledge, the classification of the 
Palaeozoic orthopteroids is necessarily based on the venation of the 
fore wings, the hind wings and body structures being very little 
known at best and entirely unknown in by far the majority of species. 
Since considerable difference of interpretation exists in even the re- 
cent literature on the orthopteroid venation, I consider it necessary 
to present here my own views on the homologies of wing veins in 
these particular insects and indeed in insects in general. I find that 
few students of insects have any understanding of the problems of 
vein homology or of the current status of the subject. The following 
account is intended to present the background and the nature of my 
own views used throughout this paper and the subsequent parts in 
the series. 
Although some preliminary attempt was made by Hagen (1870) 
to homologize the wing veins of insects, Redtenbacher (1886) was 
the first to make a significant contribution to the subject. He pro- 
posed the recognition of six main veins, which he termed the costa, 
subcosta, radius, media, cubitus and anal. In reaching his conclusions, 
he considered the general correlation of the positions of the veins, 
as well as a primitive alternation of topography, i.e., convexity and 
concavity. The Redtenbacher System of nomenclature was followed 
by Comstock and is actually the one which has been in general use, 
although it is commonly referred to as the Comstock-Needham Sys- 
tem. 2 Comstock’s first publications on wing veins appeared in 1892. 
In 1895, J. G. Needham, then a graduate student under Comstock, 
began a new approach to the study of wing vein homology and the 
ontogenetic development of wings and their veins. Results of these 
studies were first published in a series of articles under joint author- 
ship of Comstock and Needham in 1898 and 1899. An extensive 
series of papers, mainly by Needham, appeared in subsequent years 
and in 1918 Comstock brought together in book form a compilation 
of what had been done in his and Needham’s laboratories. They con- 
cluded that the various patterns of wing venation in insects had been 
derived from a common ancestral type and that the veins of different 
orders could be homclogized. The Redtenbacher System of nomen- 
clature was used by them, although no significance was attached to 
the convexity or concavity of the veins. 
As noted above, the innovation brought into their venational studies 
was the ontogenetic method. Noting that in such primitive insects 
: Comstock himself pointed out (1918, p. 11) that this nomenclature should 
be recognized as the Redtenbacher System, not the Comstock-Needham 
System. 
