8 INTRODUCTION. 



rectly extended, circularly bent, or otherwise disposed, tliej 

 cannot manifest any other relations than those that refer to the 

 structure of a single organ ; and thus, all arrangements must 

 be merely artificial, as we have no means of disposing our 

 descriptions of species otherwise than in elongated series. The 

 only remedy is to indicate in words all the relations that have 

 been observed, while some principal organ is chosen as a gene- 

 ral medium of connection. 



It is only, however, in a systematic arrangement embracing 

 all the kno^AHi species that a nice attention to their location, 

 and to the subordination of characters is of importance. In 

 the Fauna of a district or country, the gaps would be so nu- 

 merous as to break off the affinities at every step. My ideas 

 of a general arrangement of birds being as yet very imperfect, 

 I will not obtrude them at present upon the public ; but dis- 

 pose the species with which we are more immediately concerned, 

 in such an order as may preserve some of their principal points 

 of connection. 



As the limits of the genera are continually fluctuating, the 

 names imposed uj)on them are liable to frequent change, in so 

 much that in twenty years an ornithologist may liave seen a 

 given species referred to three or four genera. These changes 

 cannot be avoided, and therefore it is useless to cry out against 

 them. But as the species have a real existence, and being 

 once correctly described can always be recognised, the names 

 imposed upon them by their discoverers ought never to be 

 altered. If the specific name be fixed, it is not of much im- 

 portance that it be coupled with this or that generic name. 

 Those imposed by Linnseus, the first great reformer of natural 

 history, ought to be held inviolable, as well as all that have 

 been applied by the principal systematic writers. There are 

 cases, however, in which, owins^ to a faultiness in its construc- 

 tion, its inapplicability to the species, its leading to misconcep- 

 tion, or its manifest absurdity in some respect or other, a 

 specific name ought to be rejected. When a group is broken 

 up, a specific name ought never to be converted into a generic 

 one, although this has been a prevailing practice in Botany as 

 well as in Zoology ; for the alteration thus made is productive 



