SYSTEMATIC BOTANY. 



conditions of stem and leaf the two most fre- 

 quently graduating into each other, and forming 

 neither true leaf nor stem, but thin expansions, 

 termed thalli. Cryptogamic plants do not origin- 

 ate from seeds, containing embryos, like the 

 flowering-plants, but are reproduced by means of 

 spores bodies which in their simplest form con- 

 sist of a single cell, but which are very varied in 

 morphological character in different families. There 

 are two sub-classes. 



I. ACROGENJE. 



*Filices Ferns. *Equisetaceae Horse-tails. 



Lycopodiacese Club-mosses. *Musci Mosses. 

 *Marsileaceae Pillworts. *Hepaticae Liverworts. 



FILJCES. In this order the different parts of 

 the plant spring from a rhizome, or root-stock ; 

 the elegant fronds or leaves being either separate 

 and independent, or uniting by their stalks so as 

 to form a sort of trunk, as in the tree-ferns. The 

 fronds are furnished with forked veins, and are 

 usually pinnatifid, and more or less compound ; 

 sometimes nearly simple and entire ; in their ver- 

 nation they are circinnate that is, they unroll 

 from the stem outwards in the form of a crosier. 

 The reproductive organs appear on the mature 

 plant in the form of son, or brown membranous- 

 looking spots, usually either upon the backs of the 

 fronds, or on their margins. These sori either lie 

 under a small shield-like indusium, or they are 

 naked ; or they are arranged along the margin 

 of the leaf, which curls over them, and supplies 

 the place of the indusium. Each sorus consists 

 of a number of brownish bodies, called thecce, or 

 sporangia, each being in reality a case containing 

 a number of minute spores, which are the true 

 reproductive bodies. (For details of the develop- 

 ment of these spores into plants, see VEGETABLE 

 PHYSIOLOGY, page 75.) 



The Ferns are divided into the following sub- 

 orders : I. POLYPODlACEjE ; sporangia in vari- 

 ously shaped sori on the back or margin of the 

 frond, each having an elastic ring or rachis (verti- 

 cal and incomplete, or horizontal and complete), 

 by means of which the ripe sporangium is torn so 

 as to set the contained spores free. 2. OSMUN- 

 DACEj*E ; sporangia on a transformed contracted 

 frond, with a terminal or dorsal ring more or less 

 complete, reticulated, and opening vertically. 3. 

 OPHIOGLOSSACEJE ; sporangia in spikes, sessile 

 on a contracted frond, exannulate, two-valved 

 (vernation ' of frond straight). 4. DAN^EACE^E ; 

 sporangia dorsal in masses, exannulate, splitting 

 irregularly by a central cleft. The first sub-order 

 is illustrated by the following 

 genera : Polypodium, the poly- 

 pody, which has naked sori ; 

 Lastrea, the shield-fern; Cysto- 

 pteris, the bladder-fern ; Asple- 

 nium, spleen-wort ; Pteris, the 

 common brake ; Athyritim, to 

 which belongs the lady-fern of 

 our woods ; Adianlum, maiden- 

 hair ; and Scolopendrium, hart's- 

 tongue, the frond of which is 

 tongue-shaped and simple. The 

 second sub-order is represented 

 by Osmunda, the Royal fern ; 

 Anemidictyon, and Lygodium, 

 the climbing-fern. The third sub-order contains 



Tree-fern. 



Botrychium, the grape-fern or moon-wort; and 

 Ophiglossum, the adder's-tongue ; and the fourth 

 sub-order, a few exotic genera. The Filices are 

 widely distributed, delighting in humid soil and 

 shady situations some growing on trees. 



The fronds of the family generally contain an 

 astringent mucilage, and are thus considered as 

 pectoral; the roots of some have recently been 

 used successfully as anthelmintics and purgatives; 

 and Aspidium fragrans has been employed as a 

 substitute for tea. The young leaves and rhizomes 

 of some New Zealand species are edible ; and the 

 fronds of the common brake, when burned, yield 

 a considerable quantity of alkali. 



Lycopodiacea (Club-mosses), Eguisttacea(Horse- 

 tails), and Marsileacea (Pillworts), are usually 

 classed as FERN ALLIES. They display consider- 

 able variety of structure, and will well repay care- 

 ful study. 



Musci. The Mosses present many points of 

 interest. They are minute plants, with erect or 

 creeping stems and small leaves, all their tissues 

 cellular. At certain seasons, little flower-like 

 heads are produced, some containing antheridia 

 (so named from their resemblance to anthers), 

 and others less conspicuous, consisting of pistil- 

 lidia, which represent the female parts. At matu- 

 rity, each antheridium opens at the apex, and 

 emits a granular gelatinous mass ; this consists 

 of minute spermatozoa, which find their way into, 

 and impregnate the pistillidia, and thus give rise 

 to the development of the latter into an urn- 

 shaped theca or spore-case, containing spores 

 capable of germinating into new plants. 



Mosses grow usually in shady situations, and 

 are abundant in moist, temperate countries. They 

 are divided into three sub-orders Andreaeaceae, 

 Sphagnaceae, and Bryaceae. The first is illustrated 

 by the split-mosses (Andrecea), which are common 

 on the Scottish hills ; of the second, Sphagnum, 

 bog-mosses is the only genus ; while the third 

 embraces the genera Bryum and Hypnum, and 

 most other British mosses. 



2. THALLOGEN/E. 



The orders under the Thallogenous sub-class 

 of Cryptogams are : 



Lichenes Lichens. 

 *Fungi Mushrooms. 



Algse Sea-weeds. 

 * Characez Chans. 



LICHENES. Lichens form not the least inter- 

 esting section of the Cryptogamia, and their value 

 on the score of utility is by no means unim- 

 portant. They are familiar objects to all in the 

 form of apparent discolorations and incrustations 

 on old walls and rocks ; but some of them hang 

 in festoons from the branches of trees (Usnea, 

 Alectorid), while others (Peltided) spread their 

 thalli among mosses and herbage in shaded situ- 

 ations. They grow slowly, and attain an extreme 

 age, as some of those growing on the primitive 

 rocks of our highest mountain-ranges must be. 

 'The hoary Usneas, Ramalinas, and Physcias, 

 like the gray beard of an old man, silently but 

 eloquently proclaim time's ravages, and illustrate 

 the constant succession of life upon death, growth 

 upon decay, which is going on around us.' In 

 their reproductive organs, they approach the 

 Fungi, but are well distinguished by the presence 



