CLASSIFICA TION, 69 



The next difference to be noticed is that between 

 Gymnos'permm} which includes the Kaffir Bread, the 

 " Yellow-woods " and " Cedars " of South Africa— and 

 Angiospermce?' In the former the ovules are on the 

 edges or base of a so-called ovuliferous scale. It used 

 to be called a " carpellary " scale, because it seems to 

 take the place of a carpel ; but it is never closed over 

 the ovules, which are quite exposed, and receive the 

 pollen without any stigma on a style, down which the 

 pollen-tubes can grow; but these at once enter a 

 little hole, called the micropyle {i.e. little gate) in the 

 ovule itself. 



Gymnosperms and Cryptogams were the earliest 

 terrestrial plants known, and composed our coal. 



Class I. Dicotyledons. — All members of this group 

 are known by the following characters, allowing for 

 a few exceptions : — 



1. The parts of some, if not of all the whorls of 

 the flowers are generally in fours, fives, or many. 



2. The wood of such as are shrubs or trees shows, 

 when cut across, concentric circles, really the cut 

 cylinders of wood, having a distinct pith, or medulla, 

 in the middle and radiating medullary rays (well seen 

 in oak-wood, and called the " silver-grain " by 

 carpenters). Outside is a separable bark. 



3. The leaves are net-veined, or reticulated. This 

 means that the framework, composed of "ribs" and 



* I.e. "naked-seeded." ' I.e. " seeds in a vessel," or pericarp. 



