MONOCOTYLEDONS. 59 



this plant the fruit is closely invested by the pales, which 

 form a sort of spurious pericarp, as in Barley and Oats of 

 temperate countries, in which species the fruit becomes 

 actually adherent to the investing pales, which can only be 

 removed by grinding. The seeds of all of these, however, 

 are albuminous, corresponding, in this respect, to the seed 

 of the Castor-oil plant. 



9. There are plants presenting so many characters in 

 common with the five last examined as to be universally 

 classed with them, although they may differ from them in 

 the absence of albumen in the seed, and in other points, 

 just as the Pea differs from the Castor-oil amongst Dicotyle- 

 dons. But whether albuminous or exalbuminous they are 

 all Monocotyledons, with rare exceptions, so that this 

 term comes to be applied to a second great Class, just as 

 Dicotyledons is applied to the members of the class of 

 which we previously examined representative types. The 

 five plants which we have just examined all have monocoty- 

 ledonous embryos, excepting Dendrobe, which is exceptional, 

 in having an embryo destitute of a cotyledon ; they all have 

 parallel- veined leaves, excepting Colocasia ; and those with 

 a perianth have its parts in threes. Now these characters, 

 supported by others derived from the internal structure of 

 the stem, are, as a rule, common to all Monocotyledons, 

 and in contrast to those characters which we have shown to 

 prevail amongst and to mark Dicotyledons. 



All flowering plants are either 



\ 



Angiosperms — With their ovules enclosed in the ovary of a pistil, and fertilised by 

 pollen-tubes through the medium of a stigma : 



Dicotyledons, or Monocotyledons, 



/With 2 cotyledons, the radicle 

 ( itself usually elongating . 



Net-veined 



Parts in 4's or 5's . ... 



In a continuous ring . . . 

 Or Gymnospkrms — With their ovules open, and fertilised by direct contact of the 



Embryo 



Leaves 



Perianth 



Wood 



With I cotyledon, the radicle 

 usually remaining undeveloped. 

 Straight-veined. 

 Parts in 3's. 

 In isolated bundles. 



