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case the whole plant can be dipped in a pailful of the solution 
the result is even more certain. Ordinary soap-suds is of use, 
although greatly inferior to whale-oil soap; it should be used 
in the same way. 
Tobacco decoction is largely used as a wash and sometimes 
is very efficacious. 
Alcoholic extract of pyrethrum may benused with great ef- 
fect when only a few plants are to be protected, as in conser- 
vatories and among house-plants. This extract is made by 
soaking 50 grams of buhach or pyrethrum in 200 cc. of 95 per 
cent alchohol for about a week. It should then be filtered and 
applied with an atomizer to the plant, after diluting it with an 
equal amount of water. Thedry pyrethrum is useful, although 
it looses its strength very quickly when exposed to the air. 
Fumigation is perhaps the remedy most generally practiced. 
It consists in allowing the dampened refuse of tobacco, such 
as Stems and fragments of leaves, to smolder in a closed room 
or some confined place in which are the plants to be fumigated. 
This can sometimes be done with house-plants by throwing a 
blanket over the plants, and allowing this to confine the smoke 
which is generated by the side of the plant. Care must be 
taken not to fumigate too strongly or too long, as otherwise we 
may injure the plants. 
SCALE-INSECTS OR BARK-LICE. 
(Coccidee.) 
This group of insects takes its name from the scale or cover- 
ing with which most of its members are provided. They are 
nearly all minute insects, the scale rarely measuring more than 
one-eighth of an inch in size, most of them being even smaller. 
Some of the insects included in this family, on account of the 
affinity in structure, though unprovided witha scaly covering, 
grow larger, as the cottony maple scale. The young of these 
curious scale-insects are small, oval lice, which run about 
actively for a few hours or days, and during this period may 
occasionally be carried upon the feet of other insects or birds to 
- distant places, thus starting new colonies in case these latter 
alight on the proper food-plants. Ina short time, the young louse 
settles down, inserts its beak in the plant and finding there a 
suitable source of food, commences to grow. Before long, 
