224 MR. F. P. PASCOE ON THE COLEOPTERA OF PENANG. [May 8, 



dary, is taken by them as a fatal proof of the weakness of the posi- 

 tion. As neither genus nor species has any absolute existence, and 

 these terms can only be used to express "categories of thought," it 

 cannot be expected that they should be defined with absolute cer- 

 tainty ; and as there must necessarily be varying degrees of preci- 

 sion, some of these definitions might be so slight as to leave it doubt- 

 ful if any distinction at all could be maintained. It is true that, 

 owing to" the more or less exceptional isolation of many genera, a 

 very clear and decisive description may be given of them ; but then 

 it can never be said how soon the discovery of another form or species 

 may upset the characters we have drawn from our limited number 

 of examples, or whether the new genus or species may not be the 

 other sex of some other species. These are questions which, when 

 they occur, can only be solved by the possession of data suited to 

 each. In the meantime our best efforts can only be tentative. 

 Moreover there are many natural assemblages of species, whether we 

 choose to call them genera or not, for which no technical characters 

 can be found, their connexion depending partly on peculiarities which 

 it is scarcely possible to convey an adequate idea of in words, partly 

 on such gradual modifications of characters that no satisfactory line 

 can be drawn between them, but which are, notwithstanding, not 

 less real or striking. Those who only select a few prominent forms 

 for description may demur to this; but anyone who has gone con- 

 scientiously through a large collection will acknowledge how difficult 

 it is, in many instances, to say if geuera really exist even as a col- 

 lective term for any limitable number of species, and how unsatis- 

 factory is any attempt to combine species into genera, or individuals 

 into species, "or to distinguish hybrids* from what we conventionally 

 call "true species." It will therefore be readily understood that 

 many genera can only be vaguely defined, either from the absence 

 of salient characters, or from their gradual modifications ; and some 

 of the most natural groups among the Coleoptera might be cited as 

 examples of these classes. To argue that genera ought to be ignored 

 when not strictly defined, would, in entomology, be to make classifi- 

 cation impossible ; to say that recognized genera should be enlarged 

 from time to time to admit aberrant forms would be merely to create 

 repertories of incongruous species. 



These remarks, which may be considered almost out of place when 

 discussing a collection so distinctive in all its aspects as the one 

 before us, are rather directed to a class of critics who, looking on 

 from afar, are troubled lest they should be overwhelmed by the ex- 

 cessive multiplication of genera. My object has been to show that 

 genera may be not the less natural because founded on secondary 

 characters, and that they must be so formed if we would avoid a 

 greater evil than any multiplication of them would be, namely, put- 

 ting species into genera where no one would think of looking for 

 them. It is quite true that genera have been excessively multiplied 



* No doubt many of our so-called species are hybrids ; but a majority of these 

 obscurer species do not appear to possess the intermediate characters we should 

 expect to find if their ex : stence were due to hybridity. 



