V. 



The Structure and Habits of Archaeopteryx. 



III. — The Feathers. 



THE evidence obtainable does not justify the expression of any 

 opinion as to whether the body of Avchaopteryx was covered with 

 feathers all over or only partially. Three chief kinds of feathers 

 are, however, recognisable in the fossils: — (i) quills, (2) coverts, and 

 (3) contour feathers. 



The quills are exceedingly well-preserved, especially in the 

 Berlin specimen. The remiges, or wing-quills, had the characters of 

 those of many ordinary birds, such as a pigeon. The calamus is not 

 clearly seen, as it is hidden by the coverts ; but the narrowing of the 

 vane near the base shows (e.g., in the second and third primary quills 

 of the left wing of the Berlin specimen) that its length was much 

 the same in proportion to the rest of the feather as in the corre- 

 sponding feathers of a pigeon. The rachis is clearly seen, and is 

 slightly curved so as to render the ventral surface of the wing concave 

 and the dorsal surface convex. It tapers gradually as in feathers of 

 the usual type. The groove seen along the dorsal surface of the 

 rachis is probably due to shrinkage of the medullary substance during 

 fossilisation — but this point is open to dispute. The vane, as in 

 nearly all birds, is curved, the anterior and narrower moiety much 

 more strongly than the posterior, which latter is overlapped dorsally 

 by the anterior portion of the feather next following it. The barbs are 

 easily seen, even in photographs ; but I have been unable to make 

 out the barbules with certainty. Their existence, and even that of 

 the hooks which serve to maintain the relative positions of the barbs, 

 is safely to be inferred from the extreme regularity with which the 

 barbs lie side by side in the Berlin specimen. 



Of the quills, there are in each wing seven primary and ten 

 secondary. The lengths of the primary quills, i.e., of the quills borne 

 by the metacarpals and phalanges, are as follows (commencing with 

 the first) : — 65,90, 120, 125, 135, 130, and 120 mm. The secondary 

 quills, borne by the ulna, are not easy to measure accurately, but they 

 diminish gradually from the carpal region to the elbow. The first is 

 115 mm. long; the last or tenth, 75 mm. Taken as a whole, these 

 remiges, though less numerous than in most modern birds, are as 



