5(> 



IIARDWICKE'S SCIENCE-GOSSIP. 



to the two rows of barbules, and the vertical limb 

 the barb. The barbules are nearer the outer surface 

 of the feather, just the opposite surface to that repre- 

 presented in Fig. 41. It is evident that one row 



L.U. 



Fig. 41. — Quill Feather, under surface: hi, inferior umbilicus; 

 c, calamus, or quill ; r, rachis ; s, stem ; su, superior um- 

 bilicus ; v, vexillum, or vane composed of barbs. [J. R. L.] 



will be nearer the insertion of the feather than the 

 other. The former we will call the proximal and the 

 latter the distal row. The distal row of barbules are 

 flat and broad at one end, but narrow, branched, and 



hooked at the other, as shown (d) in Fig. 42. The 

 proximal row of barbules are also flat, broad at one 

 end and narrow at the other, but are not branched. 

 The narrow ends interlace, making the whole row 

 look like a step-ladder. We can foresee what 

 will happen when two opposite rows come together 

 naturally, viz., the distal row of one barb and the 



Fig. 42. — Diagramatic drawing of the relaticns of btrbs and 1 

 barbules. [J. R. L.] 



Fig. 43. — Diagram of the interlacing of barbule I. [J. R. L.l 

 (* Not shown, so as to avoid complications.) 



proximal row of the one next to it. What occurs is 

 represented very simply in Fig. 43. The bird, by 

 passing the feather through its mouth, lifts the distal 

 hooked row of barbules on to the proximal row of 

 the next barb, the hooks and branches of the one 

 catching the ladder-like arrangement of the other and 

 thus causing the barbs to adhere. A simple experi- 

 ment will verify this explanation. Take a quill 



