THE SEED 49 



dark triangular area ; on the Broad-bean two brown 

 spots in the same place. This is termed an aril. It 

 is much larger in some seeds, as the Nutmeg where 

 it extends almost all over the seed in red finger-like 

 processes. In the Korukapuli it extends half over the 

 surface as a yellowish-white body. But it is not a 

 necessary part of any seed, and is altogether absent 

 from those of most plants. 



Now take a Castor-seed. It is oval in outline ; 

 with a slight ridge down the middle of one side. This 

 ridge is the raphe, and where it ends is the chalaza. 

 At the other end of the seed is a yellowish-white 

 outgrowth called the caruncle ; this occurs in very 

 few seeds, being peculiar to the Castor and plants 

 allied to it. It surrounds the micropyle, which can 

 be seen as a minute hole at its end. The hilum 

 is almost too small to be visible, but on breaking 

 open a pod that is not quite ripe, we may see that 

 the seeds are attached, one in each chamber of the 

 pod, by short stalks just under the caruncle, so that 

 the raphe. runs down from the hilum, as it does 

 in the Bean seeds, and is clearly seen as a slight 

 ridge. 



Sow seeds of the Broad-bean, Brown-bean, Gram, 

 Melon or Cucumber, Castor, Date, Onion, Maize, and 

 any other kinds you like, in pots of soft sandy soil 

 and keep them moist, covering them with a plate 

 of glass or wood. All these seeds, except the Maize, 

 have a hilum and micropyle, though these are some- 

 times very difficult to make out. In the Melon-seed 

 they are close together at one end, and it may not 

 be easy to make out which is which. The Date-seed 

 4 



