STRUCTURE AND HABITS OP ARCHJ50PTBRYX. 279 



Coverts are recognisable with certainty over the primary and 

 secondary quills of the wings, especially the left wing, bnt they are 

 not nearly so well preserved as the more robust quills. They appear 

 to have been very slender, and now lie at an angle of about 40° to the 

 quills. This deflection may have been due to the action of a stream 

 of water passing over the dead bird when it first came to rest where it 

 was finally fossilised; and, if so, the animal must have come to rest 

 with its head up-stream, as one would naturally suppose. 



The appearances in the fossil do not justify any statement as to the 

 coverts in the tail or over the tibial quills. 



Contour feathers may be recognised with certainty only in the 

 cervical region. Three are well preserved between the right hand and 

 the label bearing the number 11 in Plate XV. I believe I have recog- 

 nised others ventral to the fourth and fifth cervical vertebrae ; but 

 this is far from certain. As to the covering of the rest of the body, 

 we ai'e in the dark. 



III. — Habits. 



Archceopteryx was an arboreal quadruped fitted for flight, if not for 

 prolonged flight. 



First, as to quadrupedalism and attitude. — I have already (p. 272) 

 pointed out that the digits I, II, III of the hand are long and slender 

 and flexible; and that each metacarpal and phalanx of these digits is 

 curved, the concavity being ventral ; and that the tubercles for the 

 insertion of the flexor and extensor muscles of some of these phalanges 

 are distinctly recognisable. To this I would now add that their joints 

 are at different levels, showing that each finger could be flexed in- 

 dependently of the rest, and therefore that they were free and not 

 bound together. I also showed that they did not support the quills, 

 but were free from the wing except at their carpal ends. If they were 

 bound together in the wing they would be inflexible, inasmuch as the 

 joints of each digit are at different levels from those of the other digits. 



The absence of that shifting backwards of the heavy abdominal 

 viscera which is seen in such bipeds as birds, squirrels, kangaroos, 

 dinosaurs, etc., and the lizard-like form of the body, are so clearly 

 shown by the ventral ribs that it is obvious that its centre of gravity 

 would be in front, not only of the acetabulum, but of the knee. If 



