The Woodhewer Family. 259 



dming room, and, concealed under a piece of furni- 

 ture, would continue uttering its evening song for 

 an hour or longer at short intervals, and rendering it 

 so perfectly that I was greatlv surprised to hear it ; 

 for a thrush or other songster at the same period of 

 life, when attempting to sing, only produces a 

 chirping sound. 



The early singing of the oven-bird fledgling is 

 important, owing to the fact that the group it 

 belongs to comprises the least specialized forms in 

 the family. They are strong-legged, square-tailed, 

 terrestrial birds, generally able to perch, have 

 probing beaks, and build the most perfect mud or 

 stick nests, or burrow in the ground. In the 

 numerous tree-creeping groups, which seem as 

 unrelated to the oven-bird as the woodpecker is to 

 the hoopoe, we find a score of wonderfully different 

 forms of beak; but many of them retain the prob- 

 ing character, and are actually used to probe in 

 rotten wood on trees, and to explore the holes and 

 deep crevices in the trunk. We have also seen that 

 some of these tree-creepers revert to the ancestral 

 habit (if I may so call it) of seeking their food by 

 probing in the soil. In others, like Dendrornis, in 

 which the beak has lost this character, and is used 

 to dig in the wood or to strip off the bark, it has 

 not been highly specialized, and, compared with the 

 woodpecker's beak, is a very imperfect organ, con- 

 sidering the pui-pose for which it is used. Yet, on 

 the principle that " similar functional requirements 

 frequently lead to the development of similar 

 sti'uctures in animals which are otherwise very 

 distinct " — as we see in the tubular tongue in 



s 2 



