Ixiv 



arratigement of the Longicorns. He does not however state that any 

 part of his perplexities arise from the premature activity of authors, 

 who have been busy in this group during the last few years, but 

 attributes them to the obstacles to classification presented by the 

 species and genera themselves. We have been accustomed to hear, 

 in various quarters, dissatisfaction expressed at the inordinate multi- 

 plication of genera of Longicorns proposed by recent authors ; the 

 complainers will not find much comfort in the recently-published 

 volume of the 'Genera.' It is true many genera, founded on local 

 faunas, have been suppressed by Professor Lacordaire, in the Leptu- 

 ridae and one or two other groups, but he has himself, throughout the 

 volume, created many others. He frequently mentions this subject, 

 and in one place states that the number will still have to be largely 

 increased. He adopts in the sub-family Prionidae 129 genera, 

 although the species are not much more than 300 ; and in the sub- 

 family Cerambycidae he admits 500 genera to 4500 species. 



The true reason of the recent great multiplication of genera in this 

 family of insects lies not so much in the fact that authors have 

 delighted to exercise their talent in the facile manufacture of genera 

 and generic names, but in a peculiarity in the mode of variation of 

 the species, which renders natural the formation of endless small 

 genera : the same peculiarity has given rise to the difiiculty, or rather 

 the impossibility (for so Lacordaire expresses it), of combining the 

 genera into higher groups, capable of being distinguished by constant 

 characters from other groups ; it is also, I am inclined to believe, the 

 originating cause of the existence of numerous anomalous forms of 

 Longicorns, which seem to depart from the type of the family, and 

 raise the difficulties of the classifier to the highest pitch. This pecu- 

 liarity consists in the tendency, in the species of Longicorns, to vary 

 in what are held, in other families of Coleoptera, to be important 

 points of structure, on which genera and sub-families may be safely 

 founded. We have proof of this kind of variability in the differences 

 among individuals of one and the same species, cases being known of 

 variation in the number of joints of the antennae, in the spinous pro- 

 cesses of the elytra and femora, and so forth. Passing from varieties 

 of the same species, to closely-allied species, the same phenomenon 

 appears in augmented proportions — antennas, legs, tarsi, even the 

 component parts of the dermo-skeleton, the sternal segments, are 

 seen to differ in the most extraordinary way ; and so on to the next 

 step of affinity, in .which, however, it often happens that all definite 



