310 Mr. Vigors's Sketches in Orn'Uhologi/. 



posUory of this kingdom. The zeal and love of science of in- 

 dividuals have indeed added considerably to the materials that 

 are open to the student ; and the liberality of scientifick men in 

 general affords every facility to the researches of those who would 

 be likely to profit by the inspection of their collections. But still 

 "many impediments lie in the way of him who founds his views 

 in zoology, chiefly on the comparison of its various subjects. It is 

 difficult to combine our observations on groups that are scattered 



in Dr. Latham's last edition of his " Synopsis" may be misconceived ; and 

 that, from the well known fact of a considerable number of the described 

 Falcones in that work being but varieties in age or sex of actual species, my 

 statement of their amounting to two hundred and forty seven may be con- 

 sidered as an exaggeration, and as introduced only for the purpose of further- 

 ing my argument. Were the number of the Falconidm however described in 

 •that work to be reduced even to one third, my argument would still hold good; 

 there would yet be a sufficient number to call for separation. But this is not 

 the point in question. I stated that the student,' who has a Linnean Falco to 

 be identified, must compare it with the two hundred and forty seven des- 

 criptions relating to the genus contained in that work. It is of no consequence 

 whether the descriptions are those of species or varieties, still they are des- 

 priptions which must be separately consulted. Even were these reputed 

 species to be admitted as varieties, and arranged in their proper stations, the 

 descriptions of them must still be separate, so strongly are they distinguished 

 from each other, and the comparison of them must still afford equal labour to 

 the student as if they were actual species. In stating therefore that the number 

 of described species amounts to that specified above, I conceive that I err 

 neither against the fact nor the legitimate modes of reasoning. The very cir- 

 cumstance itself, which is known to every tyro in Ornithology, who has gone 

 no further in his studies than M. Temminck's Birds of Europe, that the species 

 "of the Falconidee have been multiplied, ad infinilum, in consequence of their 

 apparently specifick differences, is a convincing proof of the necessity of their 

 subdivision by decisive generick characters. Hitherto they have been sepa- 

 rated by their diiferences only in size or colour, by the stri(e or the 

 fascite of a feather. These confessedly vary by age, by sex, by accident. 

 But the generick cliaractets adopted by modern writers are constant, (one or 

 two instances perhaps excepted where age may more fully develope them ; ) 

 and as such they relieve the Naturalist from many difficulties in his investiga- 

 tion even of species. When Ije is once acquainted with the general nature of 

 the changes that take place in this family, he is led to bring together those 

 apparent species which differ only in the unimportant characters that are 

 subject to variation, by a strict attention to those more essential points vvljjch 

 are generick, and never vary. 



