INTRODUCTION 31 
was, it has been of great service to working ornithologists. In 1855 
Gray brought out, as one of the Museum publications, A Catalogue of the 
Genera and Subgenera of Birds, a handy little volume, naturally founded 
on the larger works. Its chief drawback is that it does not give any 
more reference to the authority for a generic term than the name of its 
inventor and the year of its application, though of course more precise 
information would have at least doubled the size of the book. The same 
deficiency became still more apparent when, between 1869 and 1871, he 
published his Hand-List of Genera and Species of Birds in three octavo 
volumes (or parts, as they are called). Never was a book better named, 
for the working ornithologist must almost live with it in his hand, and 
though he has constantly to deplore its shortcomings, one of which 
especially is the wrong principle on which its index is constructed, he 
should be thankful that such a work exists. Many of its defects are, or 
perhaps it were better said ought to be, supplied by Giebel’s Thesaurus 
Ornithologiz, also in three volumes (1872-77), a work admirably planned, 
but the execution of which, whether through the author’s carelessness or 
the printer’s fault, or a combination of both, is lamentably disappointing. 
Again and again it will afford the enquirer who consults it valuable 
hints, but he must be mindful never to trust a single reference in it 
until it has been verified. It remains to warn the reader also that, useful 
as are both this work and those of Gray, their utility is almost solely 
confined to experts. 
With the exception to which reference has just been made, scarcely 
any of the ornithologists hitherto named indulged their imagination in 
theories or speculations, Nearly all were content to prosecute their 
labours in a plain fashion consistent with common sense, plodding steadily 
onwards in their efforts to describe and group the various species, as one 
after another they were made known. But this was not always to be, 
and now a few words must be said respecting a theory which was pro- 
mulgated with great zeal by its upholders during the end of the first and 
early part of the second quarter of the present century, and for some 
years seemed likely to carry all before it. The success it gained was 
doubtless due in some degree to the difficulty which most men had in 
comprehending it, for it was enwrapped in alluring mystery, but more 
to the confidence with which it was announced as being the long looked- 
for key to the wonders of creation, since its promoters did not hesitate to 
term it the discovery of “the Natural System,” though they condescended, 
by way of explanation to less exalted intellects than their own, to allow 
it the more moderate appellation of the Circular or Quinary System. 
A comparison of the relation of created beings to a number of inter- 
secting circles is as old as the days of Nieremberg, who in 1635 wrote 
(Historia Nature, lib, iii. cap. 3)—“ Nullus hiatus est, nulla fractio, nulla 
dispersio formarum, invicem connexa sunt velut annulus annulo” ; but 
it is almost clear that he was thinking only of a chain. In 1806 Fischer 
de Waldheim, in his Tableaua Synoptiques de Zoognosie (p. 181), quoting 
appear and remains incomplete. Had it been finished it would have been useless, 
The author had before (1831) attempted a similar act of piracy upon Wilson’s 
American Ornithology. 
