334 ORGANOGRAPHY. 



tioned, both from the tissue of the nucleus, and that within the 

 embryo-sac also, it has been proposed to call the latter e^c?ospgrwi 

 and the former jperisperm. Both endosperm and perisperm may- 

 be seen in the Nyni'phsa {figs. 737 and 742). 

 The general name oi perisperm or albumenvfiW 

 be principally used here, without reference to 

 its origin. From the above considerations, it 

 will be evident, that the nucleus of the seed 

 may either consist of the embryo alone, as in 

 the Wallflower, the Bean, the Pea {fig. 728), 

 which is alone essential to it ; or of the embryo 

 enclosed in albumen or perisperm., as in the 

 Pansy {fig. 755, aV), Oat {fig. 689, a), and 'Nym- 

 phcBci {fig. 742). We have two parts, therefore, to 

 ^'section of tifeseTd describe as constituents of the nucleus, namely, 

 of the White wa- the albumen or perisperm, and the embryo. 

 fhP ^plnhA!'n°'^l"rf ». Albiimcn ov Perisperm. — Those seeds 

 Closed in the re- which have the embryo surrounded by a store 

 bn^'-sa? o?\itei- of nourishing matter, called the albumen, are 

 lus, and on the said to be albuminous ; while those in which it 

 th?a1bun°en sui is absent, are exalbuminous. The amount of 

 rounded by the in- albumen will in all cases be necessarily in in- 

 teguments, verse proportion to the size of the embryo. 

 The term albumen will in future be chiefly employed, as it is the 

 one best understood, and so long as we recollect its nature, the 

 adoption of such a name can lead to no confusion. 



The cells of the albumen contain various substances, such as 

 starch, oily matters, &c., either separate or combined, and they 

 thus act as reservoirs of nutriment for the use of the embryo 

 during the process of germination. The varying contents of the 

 cells, together with certain diiFerences in the consistence of their 

 walls, cause the albumen to assume different appearances in ripe 

 seeds, and thus it frequently affords good characteristic marks 

 of different seeds. Thus, the albumen is described as 'mealy, 

 starchy, or fariiiaceous, when its cells are filled with starch- 

 grains, as in the Oat and other Cereal grains; it is said to be 

 fleshy, as in the Barberry and Heart's-ease, when its walls are 

 soft and thick ; when its cells contain oil-globules suspended in 

 a viscid mucilage, as in the Poppy and Cocoa-nut, it is oily ; 

 when the cells are soft, and chiefly formed of mucilage, as in the 

 Mallow, it is mitcilaginotcs ; or when the cells are thickened by 

 secondaiy deposits of a hardened nature, so that they become of 

 a horny consistence, as in the Vegetable Ivory Palm and Coffee, 

 the albumen is described as horny or corneotcs. These different 

 kinds of albumen are frequently more or less modified in differ- 

 ent seeds by the admix+ure of one with the other. 



Generally speaking, the albumen presents a uniform appear- 

 ance throughout, as in the Vegetable Ivory ; but at other times 



