INTRODUCTION. XXXVil 
valleys, which were formerly the receptacles for dry 
heaths and furze, if they increase to any extent, 
caterpillars will certainly be found in them; if 
nettles are by any means introduced, the beautiful 
butterflies which feed on them are sure to be found 
there; and.as these again increase, insectivorous birds 
will become resident on the spot. In confirmation of 
this fact, Mr Loudon says, ‘“‘ Having made some oak 
plantations, though only on a small scale, near my 
residence, I have occasionally found therein Thecla 
quercus, (Purple hair-streak Butterfly,) and Militcea 
euphrosyne,(Pearl-bordered Fritillary,) insects which 
previously had never been seen within some miles 
of the spot. I have seldom planted the Athenian 
poplar without finding it taken possession of by Sme- 
rinthus populi, (Poplar Hawk Moth,) and Cerura 
Vinula, (Puss-Moth,) and by other less common 
Phalenidee. The copious growth of broom in our 
plantations induced, for several seasons, the appear- 
ance of Phalena Spartiata, (the Broom Moth, 
Chesias Spartiata of Stephens,) a species which I 
had not observed before, and which has disappeared 
again since the removal of the broom on which the 
larva feeds. The Caterpillar of Acherontia Atropos, 
(Death’s-head Sphinx,) it is well known, feeds on 
