Anatomy of the Male Genital Tuhe in Coleoi^tera. 631 



evQn 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 tlie 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. Wiiile in plate 39 fig. 4 we are inclined 

 to consider Fseudelateropsis Handl. as a relative of Cupes 

 or Ovima. 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 {i. e. the 

 structure of the combined male and female parts), and 



aspect but not on the dorsal ; basal-piece well developed and cliitinous 

 on the ventral side ; internal sac small and very little differentiated. 

 This type is similar to Trox and some of the less specialised Lncanids. 



