105 
ENTOMOLOGICAL INTELLIGENCE, &c. 
(No. VIL.) 
HARMONIES OF NATURE EXISTING BETWEEN PLANTS AND INSECTS.— 
In reference to the circumstances stated im a preceding number, 
from which it has been inferred that silk is a modification of 
caoutchouce, it is mentioned in the “Botanist ” (vol. i. No. 69) that 
‘“‘a species of Scorzonera, which belongs to the natural order of 
plants Cichoracese, has been found a good substitute for the 
mulberry leaf in France. We have also been informed that a 
eaterpillar which forms a very large cocoon and spins a tough but 
coarse kind of silk, feeds on the leaves of the South American 
caoutchoue tree, Siphonia elastica. Led away by the apparent 
simplicity of an artificial arrangement of plants, botanists neglected 
the strong proofs furnished by the instinctive propensities of the 
whole animal kingdom, that plants which agree in structure gene- 
rally possess similar propensities. It was long known that certain 
animals fed on particular plants, and both during the last century 
and the present this fact has been adduced as an evidence of the 
paternal care of the Creator in providing food for all his creatures, so 
that each should have its allotted portion ; but it is available also 
to show the correctness of botanical analogies. In this way has 
Decandolle applied it in his “‘ Essai sur les propriétés medicales des 
plantes,” from which a few examples may be quoted. The Cynips 
Rosee and Cynips Salicis, the Cionus Scrophularize and Hypera 
Rumicis, feed upon several, sometimes all the species of the genera 
of plants, from which they derive their specific names; but upon 
no species belonging to any other tribe of plants; and indeed the 
fact of the Cionus Scrophularize feeding on species of Verbascum 
may be allowed to decide the point of the genus Verbascum belong- 
ing to the Scrophulariaceee, and not to the Solanaceze, as some 
think it does.*The Meloe vesicatoria (Spanish blistering-fly) gives 
the preference to the ash, then to the lilac, or privet, and last to the 
olive, all members of the tribe Oleacesze. The insect is never found 
on any plant of the Jasminacez, though it is not uncommon on 
willows, from which it is remarkable that manna may be obtained, 
as well as from the Ornus Europzea, or flowering ash. ‘The Pontia 
Brassice, or cabbage butterfly, feeds only on cruciferous plants, 
with the solitary exception of the Tropzeolum majus, or Indian 
