48 THE SCOTTISH NATURALIST 



After careful study of the early development of feathers 

 in many birds, Prof. Cossar Ewart has reached the conclusion 

 that the old ideas of the origin of feathers from scales, and 

 particularly the crude notion of the formation of a feather 

 by the frilling of an actual scale, are erroneous. He suggests, 

 and brings many facts to support his suggestion, that a 

 feather has never been anything but a feather, that it arose, 

 not from a scale, but from a growing point hidden beneath 

 a scale, and that whatever its subsequent development in 

 form may be, the growth of a feather from its first hair-like 

 appearance to its last complicated perfection is a continuous 

 unbroken process. 



Many remarkable observations, of which we can mention 

 only a few, are included in Professor Ewart's paper. It will 

 surprise most naturalists to be reminded that from start 

 to finish a feather must pass through several of nine recognis- 

 able stages or forms. In most of our native birds the ideal 

 stages of a flight feather, beginning in a feather papilla, 

 are the filament stage, the first down stage, the second down 

 stage, and the perfect penna or flight feather. But the 

 general opinion has been that in practically all of our birds 

 one of the down stages has been lost. The new interest 

 aroused by the discoveries of Dr Eagle Clarke and Mr 

 Pycraft of a double down stage in Penguin chicks, has led 

 to a fresh examination of the young of several common 

 birds, and Professor Ewart announces that he has now 

 been able to trace two generations of down plumage in 

 certain Ducks and Geese, and that where only one genera- 

 tion of nestling feathers occurs amongst these birds, it is 

 the second down stage that has been suppressed, and not 

 the first down stage as has generally been supposed. 



A detailed study of the growth of feathers in the Mallard 

 shows how closely the habits of a bird may be associated 

 with the development of the feather stages. The adult 

 Mallard is practically a non-diver, but the Mallard chick 

 behaves exactly like a Diving Duck. Now, in the Mallard 

 chick the tail feathers develop much more rapidly than the 

 wing feathers. Even in the egg the difference is noticeable, 

 for a ten days' embryo possesses much larger papillse in 



