94 BRITISH BIRDS. 



light on habits, and always, at any rate, contribute 

 towards our understanding of the wider problems of 

 ornithology. The study of Pterylography, founded by 

 Nitzsch just upon a century ago, has really made very 

 little progress since, and this because his work has been 

 used as though he had left nothing more to be said or 

 done in the matter. Nearly all the references to Ptery- 

 losis contained in the various text books can be traced 

 back to Nitzsch ; and his work, though good, was not 

 always accurate, for he had often to depend for his in- 

 terpretation on dried skins instead of birds in the flesh— 

 a fruitful source of error. And thus it is that all the 

 descriptions and figures of the Pterylosis, for instance, of 

 the Black-throated Biver (Colymbus arcticus) are mis- 

 leading, for they are one and all taken from Nitzsch — 

 and he was wrong ! 



But, I hear some reader of this magazine say, this may 

 be most interesting to the anatomist but it can scarcely 

 be supposed to come within the purview of the ordinary 

 student of British birds. But it does. A knowledge of 

 the Pterylosis of the Grebes would have convinced Mr. 

 Edmund Selous that he was mistaken when, in one of his 

 books, he describes the Dabchick as sending up a shower 

 of spray with a "flick" of its tail! Mr. Selous saw 

 nothing of the kind, he only thought he did. A know- 

 ledge of Pterylosis would have brought to light the 

 true nature of the plumage of the fledgling Tawny Owl 

 long before I had the good fortune to discover it : and 

 finally, it would have introduced more accuracy into the 

 figures of our native birds, most of which, in details, such 

 as the number and overlap of the wing-coverts, for 

 instance, are hopelessly wrong, so that Eagles are shown 

 with wings which properly belong to Sparrows, only the 

 mistake has been masked by enlarging the size of the 

 wing to fit the Eagle ! ! In short, then, if we want to 

 know all that can, at any rate, be discovered by busy 

 men, about our native birds, Pterylosis must be included: 

 and I propose, from time to time, to recount such facts 



