JAPANESE WORK ON DERMAPTERA. 135 



that ProdroiiiKs was so excellent a work that it contained its own cvire, 

 and this reduced to a minimum the mistakes of even inexperienced 

 recruits. But de ]3ormans' monograph of the earwigs in Tierreicli is not 

 the same remarkable lexicon as Brunner's Frodronnis. The worthy 

 author was handicapped by the form of the work, by the prohibition 

 of erecting new genera and describing new species, and even of bringing 

 it up-to-date, for many species were omitted which had been described 

 before his monograph was published. But the greatest obstacle lay in 

 the fact that the sum total of our knowledge of the group was 

 relatively so small; the number of known species has been nearly 

 doubled since 1900, and so the monographer of that date had seen 

 scarcely more than half of the species which we now know. It was, 

 of course, impossible for him to construct a system with such 

 meagre material, and it is highly creditable that he succeeded in 

 producing so good a work as he did. 



The inevitable consequence of its appearance was that many 

 entomologists not unnaturally began to try to work out collections by 

 means of this monograph. The most prominent was Dr. Verhoeff, 

 who attacked the material in the Berlin Museum. This acute 

 zoologist at once perceived the faults in the old system, which he 

 ruthlessly swept away, but he offered little in exchange; he only gave 

 us an outline of portions of a system. In the words of a well-known 

 American entomologist, he built a new house, but only erected the 

 doors and windows. His ignorance of the general literature and his 

 lack of familiarity with the actual insects involved him in numerous 

 errors. 



In the same way, Japanese entomologists sought to do original 

 work on this unsatisfactory foundation, and in the four papers quoted 

 above, we find the result of their efforts. Before criticising, we must 

 remember the difficulties under which they laboured ; remote from 

 the libraries and collections of Europe, out of touch with European 

 workers, they could never have been familiar with the actual creatures 

 about which they were reading, and so could not have been capable of 

 appreciating the relative value of many of the characters employed by 

 de Bormans, man}' of which, as time has since shown, are quite useless; 

 such are the coloration of feet and antenna, the development or 

 abbreviation of the wings and the elongation of the forceps. 

 Consequently we find the errors in their works are of two kinds, 

 unavoidable and avoidable. 



Among the more or less unavoidable errors, we may mention the 

 failure to appreciate true generic affinities and ignorance of recent 

 literature. 



But the avoidable errors are more important ; the greatest is the 

 erection of new genera based on insufficient material. The genus 

 Mesolabia, Shiraki (siiiira, III, p. 12), is based upon a single specimen, and 

 what is infinitely worse, that one a female. It ought to be a recognised 

 principle in systematic entomology, that no new species may be 

 founded upon females alone ; how much worse, therefore, is it to erect 

 a genus upon such slender foundations. In Dermaptera especially it 

 is fatal, for it is an unfortunate fact that, in many cases, not only 

 specific, but even generic, characters are discernible in the male alone. 



The second avoidable error is the description of new species with- 

 out figures. This should be condemned in Entomology as it is in 



