NATURE STUDY. 
198 
the shaft, a barb, and see how the barbs, too, have branch¬ 
es, the barbules. Figure 2 shows a barb, magnified, with 
the barbules represented as farther apart than in nature. 
Cut a vane and shaft across and show, as in Figure 3 (a, 
shaft; b, barb) how the barbs are attached to the shaft, 
like the wings of a bird; then cut a barb and show how 
the barbules are arranged in the same way—birds, vane, 
barbs, all having a similar form. Figure 
4 shows this appearance of birds in flight 
at a distance. Then show how feathers 
lap over feathers, barbs over barbs, bar- Fig. 3. 
bules over barbules, all closing tightly with the down 
stroke of the wing, all falling loose and open on the up¬ 
ward stroke. On the downward stroke the texture of a 
wing is as that of the finest silk fabric; on the upward stroke 
it is as open as the slats of a window shutter. Show how 
hollow the quill is, how the “shell'’ of the shaft is folded 
to form a tube. Compare this with bicycle tubing, so 
light, so strong. Show how the shaft of a feather was, 
perhaps, the first and finest tube construction in the world. 
Note the curve of the shaft in the wing and tail feathers. 
Find that in many birds the middle tail feather has the 
barbs of equal length ; that all body feathers are symmetri¬ 
cal. These few simple facts, once well understood—and 
they can be grasped by the 
average child in ten minutes— 
will remove all wonder how 
one can tell, upon picking up 
__ ^ _ a feather, whether it came 
- - - __ from body, wing, or tail, and 
whether from the right or. left 
Fig. 4. wing; from right side or left 
side of tail. This bit of knowledge will quicken a child’s 
observation, and will add to the pleasure of every walk 
afield throughout one’s lifetime. It is worth while. 
