54 THE BOOK OF EVERGREENS. 



of moss, lichens, and numerous fungi on the bark, but these 

 are undeniably the effect, and not the cause, thereof. 



We frequently find evergreens making short annual 

 growths and losing the foliage on the young wood, or, per- 

 haps, the bark is covered with lichens, and the leaves with 

 minute parasites; yet the primary cause that produces 

 this state of unhealthiness is not apparent. To counter- 

 act these diseases, we must consequently commence at the 

 foundation and search for and remove the cause, when all 

 the outward forms incidental thereunto will surely dis- 

 appear. 



Among the most mysterious causes of death in the Con- 

 iferae, is that of blight, which has heretofore been gen- 

 erally confined to the White Pine, (JPinus fitrobus,) and a 

 few allied species. So insidious is its approach that we 

 scarcely have become aware of its presence before the tree 

 is lost. Plants that are to all outward appearances per- 

 fectly healthy, suddenly turn yellow, the foliage whitish, 

 and death in a very short time ensues. This is the more 

 trying, as other plants closely adjoining still continue to 

 thrive luxuriantly, and by their rich, dark green foliage 

 lull us into fancied security, and then perchance fol- 

 low the course of their departed companions in a few 

 weeks. The requirements of the Sir obi group of Pines 

 differ widely from those of any other, and demand certain 

 conditions in the soil, to prevent disease and promote a 

 healthy growth. They will not succeed in a wet, undrain- 

 ed situation ; but if light and dry, their future success may 

 safely be depended on. 



The most rational cause that we can assign for the ap- 

 pearance of blight in the family of Conifers, is that due 

 to a too luxuriant growth. 



One of the newer diseases prevalent among evergreens, 

 and one from which the Stroll group of Pines is singu- 

 larly and entirely exempt, manifests itself as follows : 

 Early in the autumn a few minute spots are noticed at the 



