32 CERTHIA. TREE-CREEPER. 



the length of the second, the fourth longest, the fifth almost 

 equal, the third and sixth nearly of the same length. Tail 

 long, of twelve slightly arcuate pointed feathers, of which the 

 shafts are rather strong, and the extremities of the webs worn. 



The transition from the bill of Anorthura to that of Certhia 

 is very direct, the latter being merely more elongated and curved. 

 The plumage of the two genera is similar as to texture ; but 

 while the tail of the former is short and generally raised, it is 

 in the latter elongated, and employed in supporting the bird as 

 it ascends the trunks of trees. The toes, and especially the claws, 

 are longer in Certhia. 



The Tree-Creepers resemble the Woodpeckers in their mode 

 of progression, which is by extremely rapid short hops or starts 

 against the bark of trees, to which they cling with their sharp 

 claws. Their bill however is so slender and weak that they 

 cannot employ it in perforating the bark or decayed wood, 

 and they are therefore content with searching the chinks for 

 their food, which consists of small insects and larva?. They 

 nestle in holes, and have a rather numerous progeny. 



Very few species of this genus are known, and only one oc- 

 curs in Britain, the history of which will afford a good idea of 

 the habits of the rest. 



