444 THE ZOOLOGIST. 



certain ways seem to suggest that we have retrograded instead 

 of progressed. 



It seems obvious, if only from noting domestic varieties, that 

 animals of very different appearance may be allied and have 

 similar characteristics ; and further, that animals of very close 

 resemblance may be of remote relationship ; in short, that too 

 little allowance has been made for such possibilities as parallelism 

 and convergence. 



It would appear that we have not far to seek for the first 

 example in incorrect grouping, for it can be found in certain 

 birds, common even in the outskirts of our town3, and which we 

 might expect, from the endless number of papers and notes 

 published concerning them, would at least have been correctly 

 classified. They have been treated of by fanciers, aviculturists, 

 field naturalists, compilers of monographs, writers on county, 

 country and continental groups, systematists and scientists. I 

 am referring to such common species as the Greenfinch, Linnet, 

 and Chaffinch. 



If the reader will turn to any work on birds treating of classi- 

 fication, such as the ' British Museum Catalogue,' he will find 

 the Greenfinch (Ligurinus) placed in the first subfamily of the 

 Fringillidce, while the Linnet (Acanthis) is placed close to the 

 Chaffinch (Fringilla) in the second subfamily. If classification 

 is indeed an indication of relationship, we might expect to find 

 the two last-mentioned species more closely connected to each 

 other than either to Ligurinus. The results of interbreeding, 

 however, do not bear out this view ; Ligurinus hybridizing with 

 Acanthis, and both of these readily interbreed with Serinus 

 canarius, although all these hybrids are sterile. Fringilla, on 

 the other hand, has, as far as I know, never been satisfactorily 

 proved to have produced young with any of the above, or with 

 the birds that appear nearest to them, although copulation 

 takes place. 



To persons who have noted the peculiarities of these birds in 

 captivity or at large, this result, though contrary to the usual 

 classification, is by no means surprising. In fact, the unlearned 

 birdcatcher shows a better appreciation of the affinities of these 

 birds when he styles Ligurinus chloris the " Green Linnet." I have 

 spent a considerable time in observations on these birds, and it 



