GROSS ANATOMY OF FLOWERING PLANTS. xli 
B. POLYGYNCECIAL FRUITS, 
formed by the gynecia of several flowers. 
1. A spike with fleshy bracts and perianths— 
e.g., Mulberry . : . SoRosts. 
2. A spike with dry bracts and perianths— 
e.g., Birch ‘ : . STROBILE. 
3. A concave or hollow, fleshy receptacle, in- 
closing many dry gynecia—e.g., Fig . Syconus. 
§ 7. THe SEED. 
The seed is the ripened ovule, and as the ovule consists of a body, 
surrounded by one or two coats, or integuments, we may look for 
a like structure in the seed. However, the 
modifications which most seeds undergo vill 
render necessary some additional terms. Thus Wilt 
the outer integument is generally so thick- NN 
ened and hardened that it is commonly called \\! | 
the esta. The inner is sometimes called the : 
tegmen. In some seeds the outer coat be- 
comes fleshy, in which case they are baccate 
(berry-like); in others the outer part of the 
testa is fleshy and the inner hardened, so that Fie. XLUI.—Comose 
the seed is drupaceous (drupe-like). Occa- pie acre calic 
sionally an additional coat forms around the ovule after fertiliza- 
tion; it differs somewhat in nature in different plants, but 
all are commonly included under the name aril—e.g. in May- 
apple. 
The testa may be prolonged into one or more flat extensions; 
such a seed is winged—e.g., Catalpa. Its epidermal cells may be 
prolonged into trichomes, forming the comese seed—e.g., milk- 
weed (Fig. XLII). 
Fie. XLIV.—Embryos dissected out from seeds: 1, showing at a the “ radicle;” 
bb, the first leaves (cotyledons): c. the third and fourth leaves (pluniule). 
2, a straight embryo. 3, embryo folded upon itself (incumbent), 
