300 



PLANT LIFE. 



ami nation ; (3) upon the exterior, one or two integuments 

 more or less readily distinguishable from each other (figs. 

 343> 344, 345)- 



Fig. 743.— Longitudinal section of fruit of black pepper, containing a single seed. /V, 

 pericarp, showing two layers (the outer unshaded, the inner shaded by radial lines); 

 sc, seed-coats ; em, embryo, surrounded by en, the endosperm ; /, perisperm. Mag- 

 nified about 5 diam. — After Baillon. 



Fig. 344.— Seed of pansy, entire and halved, the latter showing the straight embryo, 

 the endosperm (white and dotted), the seed-coats ; m, micropyle. Magnified about 

 10 diam. — After Baillon. 



409. Fruit. — The growth of the embryo 

 excites not only the tissues of the ovule to 

 further development, but also the sporophylls 

 (carpels) bearing the ovules, and not infre- 

 quently even more remote parts. The carpels 

 (PAytoiaVta an< ^ tne * r contents and adherent parts, when 

 halved* ^show' fully developed, constitute the fruit. The car- 



b°rfo U nelt the P e,s are tnen knOWD as the pericarp. The 

 and" neai-'b/sur 5 changes \vlii< h the parts undergo are chiefly 

 "ndosperm! of two sorts — an increase in size and an altera- 

 dtam! — ''After ti 011 °f texture. The increase in size requires 

 no special explanation. The carpels may be- 

 come dry at maturity, or may thicken and become soft and 

 fleshy, or even juicy. In accordance with these differences, 

 two sorts of fruits are recognized, namely, dry fruits and 

 fleshy fruits. Between these, however, there is no sharp line 

 of demarcation. 



410. Dry fruits. — If the pistil contain only one or two 



