CLASSIFICATION OF THE VEGETABLE KINGDOM. 3 



with female organs of reproduction, is developed BEFORE FER- 

 TILISATION. The pollen-grains are carried by means of the wind 

 to the ovules; these enclose the embryo-sac, and are situated on 

 the open fruit-leaf (carpel), which has no stigma. 

 Alternation of generations : 



I. Prothallium = Endosperm in ovule. 



II. Leaf-bearing plant, with flowers which produce the pollen- 

 sac and ovule. 

 3 Classes : 1. Cycadeae. 



2. Coniferae. 



3. Gnetaceee. 



Division V. Angiospermae. The members of this group are 

 very similar to those of Division IV. The ovules are, however, 

 encased in closed fruit-leaves (ovary), which have a special portion 

 (stigma) adapted for the reception and germination of the pollen- 

 grains. The pollen-grains are bicellular, but with only a mem- 

 brane separating the two nuclei ; they are carried to the stigma 

 by animals (chiefly insects), by the wind, or by some other means. 

 Endosperm is not formed till AFTER FERTILISATION. Alternation of 

 generations in the main as in the Gymnosperms, but less distinct ; 

 while the sexual generation, the prothallium, with the organs of 

 fertilisation, is also strongly reduced. 



2 Classes: 1 1. Monocotyledones. Embryo with one seed-leaf. 

 2. Dicotyledones. Embryo with two seed-leaves. 



For a long time the vegetable kingdom has been divided into CRYPTOGAMS (so 

 called because their organs of reproduction remained for some time undis- 

 covered), and PHANEROGAMS or Flowering-plants which have evident sexual 

 organs. 



The first three divisions belong to the Cryptogams, and the third and fourth 

 divisions to the Phanerogams. This arrangement has no systematic value, but 

 is very convenient in many ways. 



The Cryptogams are also known as Spore-plants, since they multiply by 

 unicellular organs (spores), and the Phanerogams in contradistinction are 

 called Seed-plants (Spermaphyta), since they multiply by seeds, multicellular 

 bodies, the most important part of which is the embryo (a plant in its 

 infancy). Mosses, Ferns, and Gymnosperms are together known as Arche- 

 goniatre, fiuce they possess in common a female organ of distinct structure, 

 the Archegonium. 



1 See Angiospernise. 



