14 



ANALYTICAL CLASS-BOOK OF BOTANY. 



acquainted with some interesting and curious phenomena 

 in the elementary stages of Vegetable Life. Now we 

 are to trace the development from plant to plant, begin- 

 ning at the lowest, and ascending to the highest. 



87. Unicellular Plants. — When vegetation is 

 reduced to its simplest form, we find that the cell and 

 the plant represent each other, or, in other words, that 

 the cell is a coni;plete vegetahle. This has been already 

 foreshadowed to your mind in the philosophy of cell life 

 and growth, where each particular cell was considered a 

 complete organism (33). Now let us imagine one of 

 these cells entirely detached from the parent structure, 

 and you will have a better idea of the class of plants 

 alluded to — ^for in these the cell is completely isolated, 

 solitary in the deepest sense. 



88. The Rounded Cell. — In the Protoeoccus, or 

 Red Snow, that sometimes tinges with its crimson bloom 

 laree tracts of the Polar snow-fields, we find a structure 

 of the simplest form. Here is no organ of any determin- 

 able size, design, or form, nothing but one simple and 

 single cell. A group of these plants is seen at fig. 1, 

 Plate III., while on the right is an individual more 

 highly magnified, exhibiting also a division of its con- 

 tents into the new cells, which are already formed, and 

 ready to separate from the mother-cell. The Green 

 Snow {Protoeoccus viridis) has also the same habit and 

 structure. These plants quickly attain their growth; 

 the mother -cell, having given birth to a cluster of 

 daughter-cells, decays ; and thus the older tissues give 

 place to the new, and vegetation goes on indefinitely. 



89. The Branching Cell. — By another step we 

 arrive at a branching arrangement of the cell, which, in 

 form at least, dimly portrays the complicated organism 

 of higher structures. Such is the Bryopsis, a beautiful 

 little Seaweed (fig. 6). An Alga of still more complex 

 structure is seen at fig. 2, with rudiments of young plants 

 in the large globular cavity. Two of these young plants, 

 themselves containing younger cells, are seen at the 

 left in the same figure. 



90. Cells in Linear Series. — Progressing step 

 by step, we next find several cells disposed end to end, 

 and crowned by a globular protuberance, which vaguely 

 images the reproductive organs of higher plants ; for no 

 sooner does a plant, in its development, reach beyond a 

 single cell, than we begin to find a distinction between 

 the ofiioes of vegetation and reproduction — one or more 

 cells being especially devoted to that important ofiice by 



Simplest form of vegetation, describe. Kounded Cell, instances. Brandling 

 Cell, instances. Bread Mould, describe. What organs wanting in tbe lo\yer 

 plants ? What take their place ? ITow are Eed-Snow and similar plants propa- 



which the plant is to be continued, and its species pre- 

 served. But in none of the lower plants do we find a 

 distinct set of organs for the purpose, but only special- 

 ized cells, in which the reproductive functions go on, 

 either by a simple process of subdivision, as in the Red 

 Snow, or by the production of other cells, but -never by 

 the elaboration of any thing like a true seed containing 

 rudiments of the whole pla^it, us in the higher forms. 

 In fig. 3 is seen a species of Bread-Mould. The cells 

 are placed end to end, so as to form a kind of stalk, sur- 

 mounted by the globular cells containing the young 

 plants, which are called Spores, and are equivalent to 

 the seed of higher plants. They are discharged by the 

 bursting of the sac that incloses them. Mushrooms, 

 Moulds, and all plants resembling them, are called 

 Fungous Plants, and they belong to the natural Order 



FUNGL 



91. Branching Series. — In fig. 4 is another species 

 of Mould, in which the spores appear as if strung together 

 like beads, forming several branches, which are united 

 in a cluster at the summit of the stalk. The Blue 

 Mould, fig. 5, has a still more complex arrangement, the 

 sporiferous branches consisting of either one or several 

 rows of cells, forming a beautiful laoework, the whole 

 clustering together like a flower, at the summit of the 

 stalk. 



92. The Mushroom. — In the common Mushroom, 

 fig. 12, the specialized cells form a conspicuous arch or 

 cap, called the Pileds, as at 1 in the same figure. The 

 under side of this is thickly set with plates or gills, which, 

 radiating from the centre to the circumference, bear 

 naked spores on the summits of their cells. Lines repre- 

 senting these rays may be seen in the figure beneath the 

 pileus, 1. These plants grow with wonderful rapidity. 

 The stalk called a Stipe (at 2) is protruded from the 

 wrapper or Volva, which is seen in the swelling left at 

 the lower part of the stipe. At the left hand are two 

 young Mushrooms, with several others, in various stages 

 of development, about their roots, while at the right is 

 one further advanced. The volva is bursting, and in 

 separating from the pileus begins to discover the gills 

 beneath. 



93. Prondose Forms. — When the cells are combined 

 in a single plane, frondose (or leaf-like) forms are pro- 

 duced, as in many of the Seaweeds which collectively 

 constitute the Order Algje. Fig. 8 represents one of 

 them — a beautiful Alga, known as the Sea-fan. 



gated ? What are termed Fungous plants ? What order do thoy constitute 

 What are tbe mother-cells of the lower plants called ? How discharged ? NanH 

 the cap of the Mushroom — the plates underneath — the stalk — tlie wrapper. 



