266 M. H. Jekel — Tentamenta Entomologica. 



spots, whence we so often receive new species — may at least indicate 

 local and permanent varieties, if not really distinct species*. But the 

 question concerning such polymorphous species can only be settled 

 by the study of an immense number of specimens from all parts of 

 Europe. 



None of the North American species that I know of pertain to this 

 group. 



Sect. 4. Villosus, F., Cerasorum, Hb., and Rubidus, Sch., are 

 European species representing a group of a smaller size, having 

 elytra short, conic, and rather flattened as in Group III. To this 

 set belong a great many exotic species from Africa, India, and 

 Australia, amongst which Melaleucus, Sch., is remarkable for its 

 beauty and size, some specimens being larger than our Nucum. If 

 Schonherr's indication is not the result of an erroneous comparison, 

 the species varies very much in size, for he says, " Balanino villoso 

 dimidio major." This nevertheless would not be unlikely, for our 

 European species present great differences in size. 



This group might be subdivided into two sections according to the 

 armature of the thighs ; but Rubidus cannot be severed from Cera- 

 sorum in a natural distribution of the species, and some South African 



* Although, in a philosophical point of view, an important biological result 

 will be attained by the recent conscientious and most valuable observations of 

 Mr. Darwin (On the Origin of Species, &c., 1859) on the successive modifica- 

 tions of species through the numberless influences acting upon successive genera- 

 tions of a given type, descriptive zoology, restricted to the registration of the 

 actual differences between actual species, regardless of the possible, but un- 

 warrantable, modifications of such species a century hence, will probably always 

 see its worsliippers divided as to the limits of species or varieties. The more I 

 have studied the matter, the more I have been convinced that nature, in the 

 groups that we — more or less arbitrarily — call genera or subgenera, proceeds by 

 types, round wliich actual types (without regard to past or future modifications) 

 gravitate the so-called species, subspecies {incipient species, Darwin), and varieties. 

 It thus becomes every day more and more necessary for authors, monographers, 

 or faunists to proceed, in their enumerations and descriptions, to philosophical 

 and biological investigations of the really natural groups of species in each genus, 

 and this is what I have always aimed at in my various enumerations of species 

 in extensive groups. The continual and endless increase of materials in the 

 collections makes it a duty to conscientious authors to follow such steps ; for the 

 use of dry, short, aphoristic, and absolute descriptions (easy work !), giving no 

 idea of the aberrant constitution of a new species, are the plague of science, 

 especially when made by authors who have an insufficient knowledge of the 

 various types of a genus. The excellent application of this principle by Mr. 

 H.W. Bates ("Contributions to an Insect Fauna of the Amazon Valley," in 

 Trans. Entom. Soc. London, 1860 & 1861), enhanced by personal (ad naturam) 

 investigations — increasing so highly the value of philosophical deductions — de- 

 serves the warmest thanks of all true entomologists. 



