32 love's meinie. 



arity, that it has, as it were, projecting shoulders 

 Sit a 1 and a 2. I merely desire you to observe this, 

 in passing, because one usually thinks of the contour 

 as sweeping unbroken from the root to the point. I 

 have not time to-day to enter on any discussion of 

 the reason for it, which will appear when we ex- 

 amine the placing of the wing feathers for their 

 stroke. 



Now, I hope you are getting accustomed to the 

 general method in which I give you the analysis of 

 all forms — leaf, or feather, or shell, or limb. First, 

 the plan ; then the profile ; then the cross-section. 



I take next, the profile of my feather (B, Fig. i), 

 and find that it is twisted as the sail of a wind- 

 mill is, but more distinctly, so that you can always 

 see the upper surface of the feather at its root, and 

 the under at its end. Every primary wing-feather, 

 in the fine flyers, is thus twisted ; and is best de- 

 scribed as a sail striking with the power of a 

 scymitar, but with the flat instead of the edge. 



32. Further, you remember that on the edges of 

 the broad side of feathers you find always a series 

 of undulations, irregularly sequent, and lapping over 

 each other like waves on sand. You might at first 

 imagine that this appearance was owing to a slight 

 ruffling or disorder of the filaments ; but it is entirely 

 normal, and, I doubt not, so constructed, in order to 



