102 DICTIONARY OF BIRDS 



might stand midway. Future discoveries, which one may in all prob- 

 ability expect, will still more efface this artificial boundary (p. 1564).^ 



The great novelty of Prof. Fiirbringer's treatment of the Puititse. is not 

 merely denying their existence as a distinct Subclass, for that had been 

 done before ^ ; but his demonstration, for it amounts to that, of their 

 being the retrograde descendants of volant ancestors, and moreover his 

 opinion that they diverged at different epochs, so that the several groups 

 which now exist are not homogeneous but each had an independent 

 pedigree. This not only carries to an extreme the views first enunciated 

 by Huxley, who pointed out that each of the existing Ratite groups was 

 equivalent in rank to what is commonly deemed an "Order" among 

 Birds (though he himself refused them the title), but it also involves an 

 acceptance of the doctrine of Isomorphism, to consider which would lead 

 us quite beyond our present limits, and therefore must be here let alone.^ 

 It should be said, however, that this conclusion seems to have been slowly 

 and almost reluctantly adopted by Prof. Fiirbringer, who in the fairest 

 way states the objections that may be taken to it, though finally over- 

 riding them with the result given above.* Among the great merits of 

 this great work are the representations of a genealogical " tree " shewing 

 the descent of Birds not only vertically, and that on two sides, but also 

 horizontally at three different epochs. It is unfortunately impossible 

 here to reproduce these designs, and as without their aid no correct 

 impression of his Classification could be conveyed, it seems better to 

 abstain from any attempt to set it forth imperfectly in a linear form,^ 



^ The expectation expressed by Prof. Fiirbringer in this last sentence is a truism 

 and need not alarm any true believer in Evolution, since as elsewhere observed 

 (Geographical Distribution, page 344) it is obvious that if all creation, past and 

 present, stood before us no lines of demarcation could be drawn. The taxonomer 

 has to judge by the comparatively small number of forms left to us, and between 

 them are gaps, sometimes (so to speak) narrow cracks at others wide chasms, to fill 

 up which is often beyond the power of imagination, though we know that filled they 

 once were. Those gaps form not only convenient but the sole means of marking off 

 groups of beings, whether we call them species or sub-kingdoms. Experience teaches 

 us to expect that in time we shall partially know how some of these gaps were filled. 



^ It has been likened to Owen's treatment of them, but is really very dilferent. 

 Owen, having formerly recognized an Order Cursores (by no means equivalent to that 

 of lUiger), in 1866 declared {Anat. Vertebr. ii. p. 12) it not to be natural, which is 

 quite true if in it are placed the heterogeneous forms he then assigned to it — 

 Notornis, Struthio, Didus, Apteryx, Dincmiis and Palajpteryx, which last three he 

 said "bear affinity to the Megapodial family of Gallinse," while he considered that 

 "the Ostrich bears the same relation to the Bustards " as Notornis to the Coots ! 



^ This doctrine, like that of the Correlation of Growth, is one that may be made 

 to account so easily for many difficulties, otherwise apparently insuperable, that one 

 is inclined always to view its application with suspicion, and to be loth to invoke its 

 aid except on the greatest emergency. 



* Quite recently Prof. Milne-Edwards {Ann. Sc. Nat. ser. 7, ii. p. 134) declares 

 against the homogeneity of the "Brevipennes," and consequently admits the isomor- 

 phism of some New-Zealand and Mascarene types. 



^ It is much to he regretted that while so many works of trifling importance are 

 continually being reviewed in our scientific journals. Prof. Fiirbringer's has obtained 

 but little notice in this country. An excellent abstract by Dr. Gadow was published 

 in Nature (xxxix. pp. 150-152, 177-181) for the 13th and 20th December 1888, and 

 its republication in an accessible form would be most tiseful, since no translation of 

 the original could be hoped for. A more condensed summary, with the author's own 

 paradigm, was given by Mr. A. H. Evans {Zool. Rec. xxv. Aves, pp. 14-16), while Dr. 

 Sharpe {Attempts at Classif. B. pp. 39-43) has reproduced the original plates as well 



