DB. F. LEUTHNER ON THE ODONTOLABINI. 387 



I have much pleasure in acknowledging my obligations to Dr. Gunther, the Keeper 

 of the Zoological Department of the British Museum, and to the Entomologists of the 

 department, Messrs. Butler, Waterhouse, and Kirby, as well as to the gentlemen 

 mentioned in the last paragraph, and to Prof. AVestwood in Oxford ; Prof. Blanchard, 

 Count Constantino Branicki, and Prof. Waga in Paris ; Prof. Valery-Mayet and Prof. 

 Sabatier in Montpellier ; Prof. Brauer and Herr Ganglbauer in Vienna ; Prof. Carl 

 Vogt and Dr. Frey-Gessner in Geneva ; HeiTen Schneider and Knecht in Basel ; Prof. 

 Aurivillius in Stockholm; Herr Eitsema in Leyden; but above all to Major Parry 

 and Herr van Lansberge, without whose assistance the completion of the present 

 treatise would have been impossible. 



PART I. 



Introductory Remarks. 



Scientific observations in natural history imperatively require exactitude in observa- 

 tion, accuracy in discrimination, and precision in description. The industry of describers 

 has made us acquainted with an innumerable multitude of forms of both animals and 

 plants, and has placed an enormous mass of material at our disposal. 



But the anxiety to give names to everything has saddled science with a burden of 

 synonymy, partly due to authors being unaware of what had previously been published, 

 but partly, it is to be feared, to less excusable causes, such as vanity, and the desire to 

 write " mihi " after as many species as possible. 



But the accuracy of subdivision depends on the acumen of the describer, and is also 

 influenced by his desire to subdivide and rename, so that variable species are constantly 

 broken up into so-called new ones. As a terrible example of this tendency, I may 

 quote the case of a French botanist who has divided a very common plant, Draha verna, 

 Linn., into no fewer than sixty-five new species M This shows us that a keen observer 

 can detect many phantom species by examining a large series of any variable form, 

 however common, although other species vary very little or not at all ; and some have 

 maintained their characters with unusual constancy for thousands of years, like the 

 celebrated Taxodium distickum, which, as Heer states, is unvariable and has remained 

 unaltered from the Miocene period to the present day. But such cases are rare, and a 

 careful examination will generally detect larger or smaller differences between different 

 specimens of known species. The tendency to variation has become sufficiently familiar 

 to naturalists since the publication of the classical works of Darwin. Almost every 

 large genus contains at least one species which may justly deserve the specific name 

 of " variahilis." Such forms, as Haeckel ironically but truly observes, are always a 

 nuisance to monographers, as the notion of a species becomes greatly discredited by 



' Alexis Jordan, ' Diagnoses d'espeoes nouvelles ou mt'connuea, pour servir de materiaux a une flore reformee 

 de la France,' &c. Paris, 18G4. Compare also Planchon's criticism, " Le morceUemcnt de lespece en botanique 

 et le Jordanisme " in the ' Eevue des deux Mondes,' 15th September, 187i. 



3 M 2 



