supposed Effects of Ivy upon Trees. 29 
Another mistaken idea prevails among woodmen respecting Ivy- 
bound trees, as if the tree were bound round by Ivy, as is often. 
the case by honeysuckles, traveller's joy, and other creepers, 
which form a spiral round the stem, and may perhaps check the 
circulation of juices in the tree. But thisis not the case with Ivy ; 
it goes up straight on one side, or trails along the surface of la- 
teral branches, without attempting to girt round or form a spiral 
line, or tight bandage: on the contrary, it may be remarked that 
Ivy appears to feel its way with a sort of finger-like extremity, 
by which it insinuates itself into cavities in bark, or crevices in 
the wall, but does not affix its holders till it meets with a sub- 
stance which cannot be injured by them. Indeed, of so singular 
a nature is the mode of growth and attachment in Ivy, that it 
seems possessed of some sensitive quality; for the first effort to 
fasten itself is by a kind of gluten, or by a spongy substance like 
that by which flies walk up the smooth surface of glass windows. 
"This is particularly evident in the five-leaved Ivy ; but the com- 
mon Ivy does not attach itself to smooth or vigorous young bark 
of the trees that support it, nor will it fasten to its own shoots, 
but seems cautiously to avoid them, generally by taking a dif- 
ferent direction, and sometimes by crossing over the fibres, 
leaving a space between, for each to swell; while, on the con- 
trary, it feels its way and insinuates itself most closely into all 
cavities, particularly in old walls, which may sometimes be in- 
jured, but I believe are more often supported, by the matted and. 
reticulated fibres which hold the loose stones together. 
Linnzeus affirms that “ i£ does no injury to buildings," as quoted 
in Martyn's Miller's Dictionary, from Curtis, who afterwards 
gives his Reasons for thinking Linnzus mistaken. 'l'hese are very 
similar to those given me by the most venerable patron of Natural 
History, to whom I bow with due reverence ; but I cannot ad- 
mit 
