90 THE ROSE. 
such places care should be taken not to plant 
varieties that are known to be specially 
liable to mildew. As it is contagious, 
spreading from one plant to another, we 
should advise the destruction of such sorts 
as belong to the Giant of Battles type (see 
chapter on Typical Roses); better it is to 
sacrifice a few kinds than that all should be 
disfigured with this annoying fungus. Gen- 
erally mildew makes its appearance in the 
autumn, when the nights grow cool; at this 
season it works but little harm and may be 
disregarded, since the plants have made their 
growth and the wood is nearly, or quite, ripe. 
THE RED SPIDER is a most destructive 
little insect, which generally commits its 
ravages in the greenhouse; they only make 
their appearance when favored by a hot, dry 
atmosphere. These insects are very small, 
scarcely distinguishable by the eye, if iso- 
lated; they are of a dark, reddish-brown 
color, found on the under sides of the leaves. 
They cause the foliage to assume a yellow 
tinge, and will soon make sickly the plant 
they infest. A few applications of whale-oil 
soap dissolved in warm soft water will often 
destroy them; this can be applied with a 
syringe, taking care to throw the water up- 
ward to reach the leaves affected, late in the 
