200 SUBURBAN GARDENS 
diseases which spores cause, it is the early pre- 
ventive treatment that counts. There is really 
nothing that can be done, once the disease is 
established. 
Scale insects are likely to escape attention 
unless one is on the lookout for them; but 
worms and plant lice are unpleasantly in evi- 
dence whenever they are present, hence they 
need not be treated unless actually seen. A 
common soap spray will make short work of 
the latter, providing it reaches them all. It 
may have to be used with great persistence to 
get rid of them all, however, for they multiply 
with fearful rapidity and each one must be 
drenched with the liquid in order to extermi- 
nate them. For these belong to the same gen- 
eral class as the scale insects — the class which 
feeds on the plant’s juices rather than on its 
tissues, and cannot therefore be poisoned di- 
rectly but only by contact. Use one-fourth of 
a cake of common laundry soap to four gal- 
lons of water, dissolving by heat and applying 
hot and on successive days until none of the 
insects alive are to be found. Leaves curling 
down or back are a pretty sure sign of their 
presence, for they infest the under side which, 
drying out under their persistent little bills, 
shrinks and rolls back. Worms on the con- 
