TUBEROUS ROOTS, AND GRAIN. 345 



Mrs. B. No, my dear- the husk constitutes the 

 chaff which is separated from the grain by the operation 

 of thrashing. 



It is only in one species of corn, the Triticum Spelta, 

 which I have just mentioned, that the husk adheres so 

 firmly to the grain as to require a peculiar process of 

 grinding, in order to part them. This renders it less lia- 

 ble to the depredations of the feathered tribe, who can 

 easily pick out the naked grains of wheat from the ear ; 

 but find it very difficult to dislodge those of epotre from 

 the adherent husk. 



The seed contains the embryo plant and the albumen, 

 which is to afford it the first nourishment, and this we 

 have already said consists of fecula and gluten. 



Caroline. Since the albumen supplies so ample a pro- 

 vision for the young plant, the cotyledon of corn is not, 

 I suppose, of a succulent nature ? 



Mrs. B. I beg your pardon ; but it is so minute as to 

 afford but very little sustenance. 



The beard of corn is formed by the prolongation of the 

 husks ; it is not improbable that all species of grain was 

 originally bearded, and that many of them lose this ap- 

 pendage when cultivated in good soil. 



Caroline. The beard, then, I dare say, is the result 

 of a degenerated organ, like thorns or tendrils. 



Mrs. B. Very likely ; or at least that in a state of 

 cultivation it disappears. Of the two species, bearded 

 corn is by far the more robust ; but it has the inconven- 

 ience of being subject to retain moisture, so that in a 

 wet summer it is much more liable to injury. 



Grain may be divided into three series : 



First. That whose flowers have both pistils and sta- 

 mens, and are aggregated in the form of ears. 



Second. That with similar flowers, but in the form of 

 clusters or bunches. 



Third. That in which the pistils and stamens are situ- 

 ated in different flowers. 



In the first series, which comprehends wheat, barley 

 and rye, there are slits or cavities along the axis of the 



1866. Of the Triticum Spelta, what is saidl 1867. What pro- 

 lection does the husk affordl 1868. What does the seed contain 1 ? 

 1869. How is the beard formed, and what is thought not improbable as 

 to all grains having been bearded^ 1870. What is said comparative- 

 ly of bearded corn"? 1871. What are the three aeries into which 

 grain may be divided 1 



