200 GARDENING FOR PLEASURE. 



furnace keeping up a temperature of seventy degrees, 

 they would all die before the winter was ended, particu- 

 larly if the plants were of a half-hardy nature. If trop- 

 ical species, they might stand it better ; but all plants 

 quickly become enfeebled when kept at a high tempera- 

 ture and away from the light. 



CHAPTER XXXIV. 



INSECTS AND OTHER PARASITES INJURIOUS TO 

 PLANTS. 



WHEN insects attack plants in the greenhouse, parlor, 

 or anywhere under cover, we can generally manage to 

 get them under control; but when they attack plants in 

 the open air, it is, according to our experience, difficult 

 to destroy them. Insects are injurious to plants in the 

 open air in two principal ways : some attack the branches 

 and leaves, and others infest the roots. When insects 

 attack the roots of a plant, we have been able to do but 

 little to stop their ravages. We can manage somewhat 

 better with those attacking the leaves, but even this di- 

 vision of the enemy is often too much for us. As a pre- 

 ventive, we would strongly advise that birds of all kinds 

 should be encouraged. Since the European Sparrows 

 have favored us with their presence in such numbers, in- 

 sects of nearly all kinds have much decreased. Most 

 people will remember the disgusting "measuring worm" 

 that festooned the shade trees in New York, Brooklyn, 

 and other cities twenty years ago. These made their exit 

 almost in proportion to the increase of Sparrows, and 

 they are certainly lessened from what they were before 

 the introduction of the Sparrow. The same is true of 

 the Rose Slug. In my Rose grounds, a few years ago, 

 we were obliged to employ a number of boys for weeks 



