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SALICACEJE. 



fCHAP. 



Observe the extraordinary abundance, in the stem and 

 leaves, of spiral vessels, easily observed under the micro- 

 scope, when portions of tissue are pulled asunder: the 

 gradual development of the pitcher, which may be traced 

 from its earliest appearance, both in seedUng plants and 

 at the tip of the prolonged midrib of the leaves. According 

 to some botanists the "pitcher" is a hollow petiole, with 

 its margins united in front, bearing the blade articulated 

 to it as a "lid." Dr. Hooker's observations show that 

 the pitcher is a glandular excavation in the end of the 

 excurrent midrib of the leaf. The inner surface of the 

 pitcher secretes a fluid, in which insects are frequently 

 drowned. 



This small and very anomalous Family is confined to 

 S. E. Asia and the islands of the Indian Archipelago. In 

 Borneo some species are found with enormous pitchers. 



85. Natural Order, Salkacece. — The Willow Family. 



Trees or shrubs with unisexual (dioecious) flowers. Ovary 

 free, one-celled ; ovules basal or parietal. 



Type —Willow (Salix ietrasperma) ; or Weeping Willow of 

 gardens {S. babylonica). 



A small tree with alternate simple leaves, and axillary 

 catkins of achlamydeous, dioecious flowers. 



