POLYANTHUS. 149 



the top spit, to the depth of twelve inches, should 

 be taken out, and in the bottom of the excavation 

 should be laid a stratum of rotten cow-dung-, two 

 inches thick. This is not intended to be reached 

 except by the extreme points of the fibres, should 

 they descend so far, but to serve as a reservoir of 

 moisture, and a source of gaseous vapour to give 

 high colour to the flowers. This rich layer is to 

 be covered with a compost (described above) to 

 receive the plants ; these being put in at equal 

 distances of about eight inches apart. 



In dry weather, they will require frequent 

 watering, and especially if attacked by a species 

 of acarus, commonly called red spider, which is 

 very prejudicial to them. These little insects are 

 not so easily driven from the polyanthus as they 

 are from some other trees and plants, because 

 they can secrete themselves in the under cavities 

 of the leaves, to which water cannot be easily in- 

 troduced. Two or three applications of tobacco 

 water, thrown forcibly on with a garden syringe 

 while the lower leaves are held up, is one means 

 of ridding the plants of them ; but this will 



