HOW DID THE BIRDS FIRST FLY, PERHAPS? 9 
itself could not rise directly from a flat surface, but 
had to climb some eminence from which to launch 
itself. If it could rise from the earth, it was doubt- 
less only against a hard wind, wherein its feathered 
tail and legs (tb¢w) would act as a kite while it flut- 
tered forward with its wings. In view of this great 
length of tail still persisting in so well developed a 
bird, it seems quite probable that it (and all the flying 
lizards below it) could go forward only against the 
wind or in a perfect calm. To go with the wind they 
had to flutter backward likely as many insects do 
yet. While these long tails were quite helpful at 
first, they were shortened later, that the bird might 
better turn around and fly forward under any con- 
dition. Their loss was doubtless gradual, with the 
development of better wings. 
Perhaps there is no better place than this to com- 
bat the popularly prevailing idea that a bird’s tail acts 
as the rudder of a boat. To a slight extent in some 
birds it may, but where the wing is perfected, as in 
the swifts, the albatross and others, turning is effected 
at once with a very scant tail; and its use in flight 
always has more reference to the up-and-down move- 
ments than to the lateral. It comes into play in 
alighting (as a brake) or in rising (as a kitelike sur- 
face), and is used dexterously by the soaring birds in 
balancing themselves against varying currents of 
wind. Hence we see that the earlier and later uses 
of the tail of birds are very much the same, and that 
a large lot of unreadable history lies in the jammed- 
up caudal vertebree of the modern flier. 
