FEATHklRS OF BIRDS. 



507 



termed the vane of the feather (v.) The lines from 

 which these laminse arise, approach one another at 



231, 



the lower part of the stem, till they meet at a 

 point, where the longitudinal groove terminates, 

 and where there is a small orifice (o), leading to 

 the interior of the quill. From this part the trans- 

 parent tubular portion of the quill (r) commences; 

 and at its lower extremity (l) there exists a second, 

 or lower orifice. 



The entire organ which forms the feather, and 

 which may be termed its matrix, is represented in 

 Fig. 229, when it has attained the cylindric form 

 already described ; of which a is the apex, or coni- 

 cal part that rises above the cuticle, and b the 

 base, by which it is attached to the corium, or true 



