114 



THE SECOND BOOK OF BOTANY. 



The surfaces of seeds may be smooth, striated, 

 ribbed, furrowed, netted, and tubercular, as shown in 

 the following figures : 



FIG. 238. 



D 



Smooth. 

 FIG. 241. 



FIG. 289. 



FIG. 240. 



Netted. 



Tubercular. 



Furrowed. 



Seeds are said to be definite when few and con- 

 stant in number ; indefinite when numerous and va- 

 riable. 



Seeds are solitary when single in the ovary, or in 

 a cell of the ovary. 



The albumen of seeds is the mass of tissue in 

 which the embryo is embedded. It is said to be mealy 

 when it may be readily broken down into a starchy 

 powder ; oily, when loaded with oil ; mucilaginous, 

 when tough, swelling up readily in water ; and horny, 

 when hard, and more or less elastic. 



ALBUMINOUS SEEDS are those which have albumen. 



EXALBUMINOUS SEEDS are those in which the body 

 consists of the embryo alone. 



