ON THE DISEASES OF PLANTS. 
37 
The Ampelopsis quinquefolia and cordata are of easy and rapid growth, well 
calculated to plant against ruins or unsightly objects, but they are deciduous, and 
therefore are not a good shelter in winter. They will grow in any soil and situation, 
and may be readily increased by cuttings under a hand-glass. 
Aristolochia sipho is suitable for trellis- work in a large shrubbery, or to run 
up other trees. It is increased by dividing the roots. 
Bignonia capreolata and radicans. — These are strong growing plants, very 
showy when in flower ; they require a good deal of room, particularly the B. radi- 
cans. Any garden soil will suit them. They may be increased by cuttings of the 
young wood planted in light soil, and the pots placed in a little heat. 
Eccremocarpus scaber and longiflorus. — These require exactly the same kind 
of treatment as the Lophospermum erubescens. 
Periploca Grceca is handsome, will grow in any common light soil, and is 
readily increased by layers and cuttings. 
ON THE DISEASES OF PLANTS. 
BY ROBERT SPITTAL, ESQ. 
READ BEFORE THE CALEDONIAN HORTICULTURAL SOCIETY, DEC. 2, 1830. ALSO FIGURES OF 
SEVERAL KINDS OF MILDEW INFESTING PLANTS. 
All plants are more or less subject to disease, and unlike animals so generally 
possessed of locomotion, and thereby enabled to seek shelter from the storm, plants, 
fixed to the soil, are compelled to endure unprotected the frequently injurious 
influence of external circumstances, variations of temperature, the hurricane, and 
the overwhelming attacks of the lightning. 
Pathology of Roots. — From the important relation which the root bears to 
the rest of the plant, the latter in most cases depending nearly entirely upon it for 
nourishment, anything which tends to destroy its functions must in a great measure 
injure the health of the plant, and in cases of extensive injury even cause death. 
Wounds of Roots. — The roots of plants may be wounded by instruments used 
in working the ground, from the attack of subterranean animals, such as moles, 
rabbits, mice, and a whole host of insects, the last of which injure roots chiefly 
when in the larva state by devouring the minute rootlets ; and when these larvae 
occur in great numbers, the fibrils often suffer to a great degree, being either broken 
by those which undermine for shelter, or eaten by others, and thus the plants are in 
a great measure deprived of their wonted supply of nourishment. 
The fibrils of roots are often broken among plants of the pine tribe by being 
violently shaken by the wind, &c, and although none of the roots appear above 
ground, or even the soil seems scarcely broken around them, yet the plants suddenly 
decay, being deprived of nourishment by the loss of the tender fibres. After wounds 
