CHAPTER XI. 



Diseases and Injurious Influences to which the Maritime Pine 



is Subject. 



Sect. I. — Choking by an Over-growth of Local Vegetation. 



Besides failures in the culture of the maritime pine, attributable to 

 bad seed, and to unsuitable soil, it often succumbs to other injurious 

 Influences, which operate, not always singly and alone, but in com- 

 bination, and one preparing the way for another. It suffers from 

 cold, from hail, from snow, and from wind. When the tap-root comes 

 upon a subterranean sheet of water, a layer of compact clay, or 

 rocks somewhat coherent and continuous, it becomes covered with 

 mosses and lichens, and it languishes, and dies ; and yet subterranean 

 aridity is not less opposed to its healthy growth. 



In Sologne, where the natural shrubs are destructive to young 

 seedlings, the precaution is taken of sowing the seed on newly cleared 

 land ; and recourse is had to some of the usages of husbandry, and 

 the growth of annual crops, effective in themselves or their culture 

 in cleaning the land, to destroy the noxious plants which might 

 defile the ground to be converted into pineries. 



M. Vilmorin has recorded that in his experience the couch grass, 

 and some other of the grasses, such as the agrostis stolonifera, marsh 

 bent grass, the holcus mollis, creeping soft grass, the agrostis vulgaris, 

 fine bent grass, and many species of festuca, or fesque grass, may so 

 take possession of the ground as to prove destructive to the young 

 produce of sowings of pine trees ; and in Sologne the growth of 

 bromus, or brome grass, starves and kills the seedlings of the mari- 

 time pine, while in Gascony the broom is sown with this pine to 

 shelter and protect it in infancy against the sunshine and the sea 

 breezes ; but there the seedling pines are stifled by a vigorous growth 

 of heaths, such as the erica cinerea, the fine leaved heath, and calluna 

 vulgaris, the ling or heather of Scotland. 



Sect. II. — Destructive ravages by Birds, and Squirrels, and Insects. 



Many birds, remarks Boitel, are destructive or injurious by eat- 



