40 BRITISH BIRDS, THEIR EGGS AND NESTS. 
altogether strange and half startling, from its greatness and 
suddenness. The deep keel and the strong substance of the 
hreast-bone in the Hawk has given place to a shallow keel and 
weak walls in the Owl, while the curved, strong, broad, solid 
merry-thought has become a fork with thin, straight, weak, | 
yielding shanks. So great and plain is the difference that any 
sharp intelligent boy could almost directly pick out for himself 
all the Hawk bones, and all the Owl bones, and put them in 
their several groups. And if he did, I think he would say to 
himself, and most likely to some other person, as soon as he met 
with one likely to be able to answer him, What does this 
difference in these bones of these birds of different Families 
» mean ?—In plain words, it means difference in powers of flight. 
Any of our school-boy readers who wanted to prise his strong 
school-box open, because he had lost his key, would not take 
his pen-knife for the purpose; because he would think it foolish 
to use so weak an instrument for so strong an effort. A great 
strong chissel would be much more likely to serve his purpose. 
And so is the work of God’s hand. If a long, strong wing has 
to be moved rapidly, and even vehemently, the motion, like all 
animal motion, must be given by muscles. But the muscles 
must be fixed to what they are intended to move, or they cannot 
act on it; and they must be fixed at some other point also, or 
they would waste their power on nothing, instead of imparting 
motion. And, of course, the stronger they are, the stronger 
must waat they are fixed to be, and the larger also to admit of 
more and more strength. Well, the muscles that move the 
bird’s wing are affixed at their other extremities to its breast- 
bone and merry-thought, and hence the size and strength of these 
pones in the Falcon kind with their vigorous, impetuous flight 
wid sweep of wing; and the comparative insignificance and 
