Anatomy of the Male Genital Tube in Coleoptera. 631 
even in that case have been highly improbable that we 
could have contributed much to the elucidation of the 
enormous complex. This would be of itself a considerable 
work, 
PHYLOGENY. 
In considerations as to phylogeny, palaeontology should 
be of the first importance. Unfortunately our knowledge as 
to this subject is dreadfully incomplete and is we fear likely 
to remain so for a very long period. In fact all we know 
is that no Coleoptera have yet been found earlier than the 
Triassic period; and that long anterior to that there 
existed many insects some of which it is reasonable to 
suppose were precoleopterous ancestors of the Order. 
Handlirsch suggests Blattoid or Sialoid ancestors. Only 
18 of these ancestral Coleoptera are known in the Trias, 
and the whole of the subsequent mesozoic period only shows 
a total of 352 species. No information whatever exists as 
to the structure of the male genital tube of the fossil 
forms, so that palaeontology is of no assistance in our 
present special inquiry. All we can say is that with 
Handlirsch’s plate 41 before us, in which the remains of 
the Liassic Coleoptera are figured, we may say that a 
considerable number of the forms are such as we should 
expect to find provided with a simple trilobe aedeagus or 
a Caraboid one. While in plate 39 fig. 4 we are inclined 
to consider Pseudelateropsis Handl. as a relative of Cwpes 
or Omma. The condition of these fossil Coleoptera is, how- 
ever, such that we really learn but little from them beyond 
the existence of a number of very distinct forms among 
the earliest Coleoptera. 
In the absence of palaeontological guidance students of 
Coleopterous phylogeny have been driven to rely on other 
characters. The male genital tube has received no con- 
sideration in this respect, but we believe that it will be 
recognised as of great importance as elucidating phylogeny 
especially when it shall have been studied in conjunction 
with the female structures. There are in fact three main 
lines of inquiry as indicative of relationship, (1) the body 
and its appendages, (2) the genital conduit (7.¢. the 
structure of the combined male and female parts), and 
aspect but not on the dorsal ; basal-piece well developed and chitinous 
on the ventral side ; internal sac small and very little differentiated. 
This type is similar to 7roa and some of the less specialised Lucanids. 
