SECT, I. THE SEED. 255 



niistry, with which it is desirable that the terms of 

 botany should not interfere. The latter reason is an 

 argument of some weight against the use of the 

 term albumen ; but the former is no very strong 

 argument in favour of the term Perisperm, because 

 the organ it is meant to denote is also very often 

 surrounded by the embryo, or nearly so, and 

 situated in the centre of the seed, as in the Caryo- 

 phylltf and others. In the Grasses (PL VIIL 

 Fig. 1 .) and Malvaceous plants it forms the princi- 

 pal mass of the nucleus, though in many seeds it is 

 scarcely perceptible ; and in some, as in the seeds 

 of Leguminous plants, and plants with compound 

 flowers, it does not even exist, at least as a separate 

 organ. 



The figure of the albumen is generally that of the Figure, 

 external integuments, roundish if the seed is 

 roundish, and oval or otherwise if the seed is so. 

 But to this rule there are many exceptions, par- 

 ticularly when the albumen is central. The surface, 

 which is sometimes smooth and sometimes fur- 

 rowed, is often also interrupted with chinks or clefts. 

 When it is not itself central it contains internally a 

 cavity or cell for the embryo, and sometimes two 

 such cavities, of which the one has been said to be 

 always empty:* but this is evidently contradicted 

 by the example of the seed of the Missletoe, Viscum 

 alburn^ the albumen of which contains two cavities 

 and two distinct embryos. Its substance, though 

 * Seacb. Phys. Veg. vol. ii. p. 198. 



