THE WEAPONS AND WINGS OF BIRDS. 663 



Oue curious feature noticed with a nestling whicli liad been upset into 

 the river was its power of rapid swimming and diving when pursued. 

 As soon as the hand was placed close to it, it rapidly dived into the 

 dark water, in which it was impossible to see it, and would rise at dis- 

 tances of more than a yard away. Owing to this power, the little 

 creature managed to evade all attempts to seize it, taking refuge 

 eventually far under the bushy growth where it was impossible to pur- 

 sue it. The prolonged immersion which a nestling will thus instinc- 

 tively and voluntarily undergo, or which an adult bird will bear in an 

 attempt to drown it, seems quite remarkable. 



The nestlings, even when quite small, are frequently found far away 

 from any nest, climbing by the help of their clawed wings, after the 

 parent birds during their feeding time. 



Not the least of the many interesting features of the Hoactzm is the 

 rapid change which takes place in the fore limb during the growth of 

 the bird by which the hand of the nestling with its well-developed, well- 

 clawed fingers, becomes theclawless wing of the old bird with its abor- 

 tive outer finger. It gives us, as it were, an epitome of the past history 

 of birds, and as the events of a century are summed up in a page of 

 history so the slow progress of birds from the Jurassic Archa'opteryx 

 to the thrush of to-day is represented by a few weeks in the life of the 

 Hoactzin. 



