RELATIONSHIP OF SPECIES. 445 



is easy for anyone to note in far less the different habits of 

 Ligurinus and Acanthis on the one hand to those of Fringilla on 

 the other. 



For instance, the two former fly in family parties or combi- 

 nations of family parties ; while Fringilla proceeds in large 

 scattered hosts, each bird flying more or less individually ; and 

 what combination is present amongst them appears to result 

 more from their gathering promiscuously together on some spot 

 that affords the food desired. These remarks apply to winter 

 time when these distinctions are best noted. The demeanour 

 of Fringilla (as can be observed in captivity) is also at variance 

 with that of the others. It is a bird of far more insectivorous 

 tendencies, and from this cause has developed a prying, investi- 

 gating demeanour. It also makes use of a sidling mode of 

 progression to one side when on a twig that I have not noticed 

 in the other forms. F. coelebs and its kin (F. montifringilla, at 

 any rate) also have an unpleasant attribute in confinement of 

 hunting down and murdering other birds. To anyone who has 

 time and who will take the trouble to observe these birds with 

 something more than a mere superficial glance, these differences 

 will soon become apparent. 



As before stated, the tests of interbreeding which I have 

 made myself, and I believe those of all others, bear out these 

 deductions. It has always seemed to me that Fringilla is a 

 more generalized form, from which many other closely connected 

 forms capable of producing hybrids inter se, such as Carduelis, 

 Alario, Serinus (some), Acanthis, Pyrrhula, Ligurinus, &c, have 

 differentiated ; the two latter being apparently specialized to a 

 higher degree, but, contrary to the text-books, Ligurinus less so, 

 I should imagine, than Pyrrhula. 



Serinus also seems an ill-assorted group. Some of this genus 

 at least having a curious action after copulation, pointing bill 

 and tail in the air, and proving quite barren with S. canarius. 

 No doubt some of these Serins should come out and be placed in 

 a genus Crithagra (seed-eaters), but whether these differences 

 should be founded on the size of the bill, as has been proposed, 

 does not seem to me necessarily of consequence. 



I think that the result of all this may be summed up as 

 follow 8 : — 



