2l6 The entomologist. 



less important and have by no means been neglected in our 

 latest classifications. 



In fact, the characters to be obtained from a stud}' of the 

 external form and structure of the body should, in Kolbe's 

 opinion, outweigh all others, such as those derived from the 

 internal organs or from the structure of the various appendages 

 — wings, legs, antennse, &c. In the head, its modifications of 

 form, the presence or not of a distinct labrum, and the coales- 

 cence or otherwise of the gular sutures ; in the prothorax, the 

 extent to which, if any, fusion has taken place in its skeletal 

 parts, the pleurse with one another or with the notum or 

 sternum ; in the abdomen, the number of the segments, and, 

 especially, the separation or fusion with one another of the 

 sternites and pieurse of the basal segments — these are the 

 characters which have for Kolbe the greatest morphological and 

 phylogenetic value. The chief direction of evolution in the 

 Coleoptera has been towards a fusion of the basal sternites and 

 pleurfe of the abdomen, and also of the skeletal parts of the head 

 and thorax ; this is, I think, a fair statement of the leading 

 principle in his classification. 



It can hardly be denied that that is one direction, and a very 

 important direction, in which evolution has gone on in the 

 Coleoptera ; but it has proceeded also in many other directions ; 

 effecting changes in the structure of the wings, legs, and other 

 appendages, no less than in the body itself, and every character 

 has its value in phylogeny if it enables us to postulate of such 

 or such a form that it cannot have been derived from such 

 another. There are many characters of this kind to be met with 

 in the Coleoptera, especially if the law be true that an organ or 

 structure having once disappeared in the course of evolution 

 will never again reappear. The application of this law, enun- 

 ciated, as he says, by Meyrick, plays an important part in the 

 phylogenetic speculations of Laraeere, and there is little doubt 

 that it can, if used with care, be made to yield very good results. 

 It seems to me a safer method than that of considering one set 

 of characters all-important. 



The Rhynchophora are characterized, as a whole, not only 

 by the great concentration of the ganglionic chain but also by 

 the great extent to which fusion of the exoskeletal parts has 

 taken place, and the great modification in form undergone by 

 the head, Kolbe considers them, therefore, not only as a 

 distinct group, but as the most highly organized of all the 

 Coleoptera, and places them last in his classification. 



But he has, I think, rather over- emphasized the distinctness 

 of the group, and the extent to which fusion of the parts of the 

 body has taken place. 



Ganglbauer has pointed out that of all the characters 

 assigned by Kolbe to the Rhynchophora, only two — the coales- 



