ALBUMEN, OR NUTRITIVE MATTER. 21 
of the Seed have been noticed ; it now remains to make 
some comparisons between the structure of different 
seeds; for all seeds are not alike internally, any more 
than they resemble each other externally ; and if only 
a few be compared together, a marked difference will 
be found between them. 
Compare, for instance, the thick shell or testa of the 
common Bean with the thin brownish one of the 
Almond, which peals off so readily after it has been 
steeped in hot water, or can be. scraped off with the 
edge of a knife. The hilum, which is situated at the 
pointed end, is scarcely visible; while in the Horse 
Chestnut, the hilum is the broad whitish mark upon 
the brown seed. Let a few comparisons now be made 
respecting the internal parts in these different seeds : 
first, on opening the seeds of a Bean, Pea, or Lupin, 
(which should be done after soaking in boiling water,) 
it will be seen that the heart, or more properly speaking 
the radicle and plumule, is curved and situated at one 
side (pl. i. f. 2. r.), while in the Almond (f. 5. 7.), 
Apple, Pear, and Walnut, it is quite straight and placed 
at one end. The seed-lobes or cotyledons differ, not 
only in their form, but also in consistence, those of the 
Almond being oily, while in the Bean they are hard 
and mealy. Inthe Walnut, the seed is that part which 
is within the shell, and the yellow skin which is peeled 
off before the Walnut is eaten, is the Testa. The 
radicle is situated at one end, and the two cotyledons 
are curiously grooved and crumpled on the outside. 
19. There is another peculiarity to be noticed in 
some seeds; for example, the seed of the Beet, or 
