178 



Marvels of the Universe 



^'^ 



iBy il. Gnnwhl. 



THE BIRD WITH HANDS. 



The 



the yo-jng Hoatzin, showing the thumb and forefinger armed 

 with the long claws with which it is provided. 



de\'eloped far enough to break 

 the force of a fall, should such 

 an accident happen, the growth 

 of the outermost quills is re- 

 tarded lest they should hamper 

 the grip of the claws. But as 

 soon as the wing area is large 

 enough to support the bird in 

 mid-air, the quills held in re- 

 straint begin to grow, and with 

 their growth the claws are 

 gradually absorbed and finsdly 

 disappear. That on the thumb 

 is the first to go. By the time 

 the normal flying wing has been 

 developed, the growth of the 

 forearm has exceeded that of the 

 hand, and for ever afterwards the hand becomes the shortest, instead of the longest, segment of 

 the wing. Should one of these voungsters fall into the river below, it promptly strikes out 

 for the shore, and seizing hold of some overhanging bough trailing in the water, it speedily 

 scrambles back to its fellows ! 



Curiously enough, the wing of the young game-bird reveals incontestable evidence of former 

 similar climbing feats, thus showing that once on a time these birds also dwelt in trees, and reared 

 their young there. In such wings — and the point can be verified in the chick of anj- barn-door 

 fowl — the growth of the outer quills presents the same phenomena of development ; but to see the 

 claws we must examine the embryo. Thus it is evident that the days of arboreal nurseries must 



be remote indeed, for structures 

 which appear and disappear 

 during embryonic life can have 

 played no active part in the 

 life-history of their possessor for 

 countless generations. 



THE NESTING OF 

 CAIMANS 



BY R. LYDEKKER. 



Much confusion exists in the 

 popular mind as to the dis- 

 tinction between crocodiles and 

 alligators, Anglo-Indians almost 

 invariably speaking of the re- 

 presentatives of these reptiles 

 found in India as alligators, 

 whereas thej' are really croco- 

 diles. To point out the distinc- 

 tions between the two groups 

 is impossible on the present 



\_Ly H. annroUl. 

 THE BIRD WITH HANDS. 



The wing £t a later stage of development. Notice how the growth of the outer- 

 most quills is retarded so as not to impede the use of the claws. 



