EXTERNAL ANATOMy. — SOANSORIAL TAIL. 109 
is reduced to its minimum (e). No one, in fact, upon a 
cursory examination, would suppose that this member 
was otherwise than simply rounded ; for not only the 
webs, but the shaft is of the ordinary flexibility : upon 
a morecarefulexamination, however, it will be found that 
the shaft of each is prolonged in the form of a short se- 
taceous bristle, having a slight degree of elasticity, and 
which is entirely bare. Although scansonal tails, as m 
all the preceding instances, have the shafts of the fea- 
thers more rigid than those of the ordinary construction, 
it must not be imagined that all scansorial birds exhibit 
this formation, although they actually belong to the scan- 
sorial circle. We can, from personal observation, vouch 
for the fact that the creepers composing the genera, 
Zimops, Anabntcs, and Dendroma, are habitual climbers; 
and yet, although this habit might be inferred from 
their feet, it is by no means manifested in that of the 
tail, which, on a cursory glance, appears simply gra- 
duated: on trying its flexibility, however, with the hand, 
the shafts are found to be less pliable than in ordinary 
tails ; and in some species of Anabaien the tip projects 
beyond the webs in a slen- 
der point, in tlie same man- 
ner as in Lochmin. No ap- 
pearance, however, of this 
incipient tendency to the 
structure of De.ndroaolapteg 
is seen in the genus Dendro- 
ma {fig- 56'. b, & SJ.b'), and 
yet we have seen these birds 
running both up and down 
the trunks of trees, much in 
the same manner as their 
congeners. We have no 
doubt that the genus Syn- 
allaxis follows that of Den- 
dromUy but then it is abei- 
rant and therefore we may suppose the climbing habit 
to be less developed. It accordingly is so, for some 
