QUERCUS. 207 



The tonic Cascarilla is the bark of Croton Eleuteria of Brazil. 



Capers, used in pickles, sauces, etc., are the 3-lobed fruit of Euphor- 

 bia Ldthyris, often seen in our gardens. 



Tapioca is obtained from the Bitter Cassava (Jatropha Mdnihot), a 

 shrub extensively cultivated in S. America. Its tuberous root, some- 

 times weighing 30 Ibs., is full of a poisonous juice. In preparing it 

 for food, it is first scraped to a pulp and pressed to remove the poison. 

 The cakes of cassiva thus formed are dried and baked, making a bread 

 commonly used by the poorer classes. When the expressed juice is 

 allowed to stand, a delicate starch is deposited, which, when washed 

 and granulated on hot iron plates, forms the Tapioca of commerce. 



India Rubber is the thickened juice of Siphdnia eldstica, a tree grow- 

 ing in Guiana (see Chemistry, p. 227). 



Boxwood, used by engravers, and for mathematical instruments, and 

 also cultivated for borders, is Buxus sempermrens of Asia Minor. 



The so-called Blinding Tree (Exccecdria Agdllocha) of the Moluccas 

 has a juice so acrid that a drop falling into the eye will nearly blind it 

 an accident which is said to have happened to sailors sent on shore 

 to cut fuel. Even the smoke of the burning wood is dangerous. 



LVI. THE WHITE OAK.* 



''Not a prince 



In all that proud old world beyond the deep 

 E'er wore his crown as loftily as he 

 Wears the green coronal of leaves with which 

 Thy hand hath graced him.'' 1 



BRYANT. 



Description. A large proportion of our forest trees are 

 Oaks. Also in the open fields the Oaks stand solitary, in 

 alternation with Elms and Maples, the charm of every rural 

 scene. The White Oak will be our special theme to-day. Its 

 flowers appear in May, soon after the expanding leaves. The 



* The Oak, Pine, etc., are fertilized by the wind. It is curious to notice, in con- 

 trast with the insect-fertilized plants we have considered, the new floral adaptations 

 which here exist. The long, lightly-hung, pendulous catkins are set in motion by the 

 merest breath of air. The blossoms appear, too, in the early season when gales are 

 most numerous and boisterous. 



