164 POPULAR ERRORS. 



of sand in the soil may appear small. Silica, how- 

 ever, is not an important ingredient in plants, and 

 its presence in them is largely accidental. Still it 

 is of some use, but this is not mainly for the pur- 

 pose of stiffening them. Large forest trees, which 

 require great stiffness in their stems, contain only 

 small traces of it. In pines and other evergreens 

 it is almost wholly confined to the leaves, where it 

 is of no use for stiffening purposes. It has there, 

 however, another use, namely to protect the leaves 

 from the weather, and this appears to be its main 

 purpose in the wheat plant, for it does not occur in 

 greatest abundance in the stem, where most needed 

 if it were for stiffening, but chiefly in the leaves, 

 and especially in the chaff where it accumulates in 

 large quantity during the ripening of the grain 

 and serves to preserve the chaff from the effects of 

 moisture and thus protects the grain. 



Trijacial Oranges. J. N. Whitner, in his 

 " Gardening in Florida," gives the following 

 account of this so-called composite fruit: 



"It may interest the curious and inquiring to 

 read of, and perhaps test by experiment, the pro- 

 duction of what in some places in the East is called 

 the ' Trif acial Orange,' in others the ' Granger Her- 

 maphrodite.' Mr. St. John, in his ' Travels in the 

 Valley of the Nile,' gives the following account, 

 says Lindley, of this very curious tree, in Boghos 



