SECTION 15.] 



SEEDS. 



125 



plants. As already shown (313), these cones are open pistils, mostly in 



the form of flat scales, regularly overlying each 

 other, and pressed together in a spike or head. 

 Each scale bears one or two naked seeds on its 

 inner face. When ripe and dry, the scales turn 

 back or diverge, and in the Pine the seed peels 

 off and falls, generally carryiug with it a wing, a 

 part of the lining of the scale, 

 which facilitates the disper- 

 sion of the seeds by the wind 

 (Fig. 412, 413). In Arbor- 

 Vitae, the scales of the small 

 cone are few, and not very 

 unlike the leaves. In Cy- 

 press they are very thick at 

 the top and narrow at the 

 base, so as to make a peculiar sort of closed cone. In Juniper and Red 

 Cedar, the few scales of the very small cone become fleshy, and ripen into 

 a fruit which closely resembles a berry. 



Section XV. THE SEED. 



380. Seeds are the final product of the flower, to which all its parts and 

 offices are subservient. Like the ovule from which it originates, a seed 

 consists of coats and kernel. 



381. The Seed-coats are commonly two (320), the outer and the inner. 

 Fig. 414 shows the two, in a seed cut through lengthwise. 

 The outer coat is often hard or crustaceous, whence it is 

 called the Testa, or shell of the seed ; the inner is almost al- 

 ways thin and delicate. 



382. The shape and the markings, so various in different 

 seeds, depend mostly on the outer coat. Sometimes this fits 

 the kernel closely; sometimes it is expanded into a wing, as in the Tium- 

 pet-Creeper (Fig. 415), and occasionally this wing is cut up into shreds 

 or tufts, as in the Catalpa (Fig. 416) ; or instead of a wing it may bear a 

 Coma, or tuft of long and soft hairs, as in the Milkweed or Silkweed (Fig. 

 417). The use of wings, or downy tufts is to render the seeds buoyant 



Fig. 411. Cone of a common Pitch Pine. 412. Inside view of a separated scale 

 or open carpel ; one seed in place : 413, the other seed. 



Fig. 414. Seed of a Linden or Basswood cut through lengthwise, and magnified, 

 the parts lettered: a, the hilum or scar; b, the outer coat; c, the inuer; d, the 

 albumen; e, the embryo. 



