606 



BOTANY. 



The second order DICECIA contains plants which 

 have the polygamy complete on two different roots. 

 This order contains eighteen genera, among which 

 there are the ash tree, so useful for its timber, the 



Polygamia. 



Dioecia. 



bread nut, the date plum, the anacardium, and the 

 numerous family of the fig. Out of this last-men- 

 tioned genus Linnaeus formed another order which he 

 called TRICECIA, having the polygamy complete on 

 three distinct plants ; that is, male flowers are found 

 on one, female on another, and male and female 

 flowers on a third ; but as this circumstance has only 

 been noticed on one species, viz. the cultivated fig, 

 his followers .have thought the order untenable, and 

 it is therefore abolished. 



The twenty-fourth class is CRYPTOGAMIA, which 

 signifies hidden marriages. This class is divided 

 into nine orders, and contains three hundred and 

 seventy-six genera, ,and two thousand six hundred 

 and sixty-two species. 



The first order is FILICES, or ferns, having the 

 sporule or seed conceptacles on the back of the 

 fronds or leaves. In the Blaechnum, figured below, 

 the fructification forms lines parallel to the ribs of the 

 leaflets, while the Polypodium is so called from the 

 fructification spots on the back of the frond. These 

 are a very carious and distinct tribe of vegetables. 

 They have perennial roots, annually throwing up stems 

 or fronds, which are evolved circinately ; that is, the 

 point of the frond, and its divisions, are rolled in upon 

 their bases in their incipient state, and their develope- 

 tnent is an evolution or unrolling to complete expansion. 

 In cold countries, the ferns are what the palms are 



Cryptogamia. 



Blcecl'Dum. 



The Gun Polypodium. 



between the tropics, their appearance being somewhat 

 similar. Indeed, some of the ferns in South America 

 vie with the palms in height, though not in duration ; 

 the former being much more fugitive. The frontls 

 are kidney-shaped, linear, pinnate, or decompound ; 

 some are not more than an inch in height; others, in 

 warm countries, arrive at many feet in height. Ac- 

 cording as the conceptacles, or spots whence the seeds 

 or dust proceed are arranged on the frond, the 

 generic characters are drawn ; some, as the osmunda, 

 have their fructification in a loose spike, quite dif- 

 ferent in form from the fronds. The habitat of 



ferns is on waste ground, damp rocks, or mossy sterna 

 of trees. 



Cryptogamia. 



The Tunbridge Fern Trichomanes Tunbridgense. 



The second order, EQUISETACE./E, contains only 

 one genus, whence the name of the order is derived, 

 namely equisetum, or horsetail, a common British 

 plant found in pools and ditches. In some countries 

 this plant is called frog-pipe, because frogs are found 

 in the same situations. The horse tail is of most 

 symmetrical growth ; upright jointed stems, with 

 verticillate fringes of linear leaves, bearing spikes of 

 fructification on the summit. 



Crvptogamia 



Equisetacez. 



The third order is LYCOPODEACE.S, containing only 

 two genera. This is otherwise called club-moss, 

 from the shape of the plants. This order of plants 

 are found on peat bogs, and damp woods of peaty 

 soil. 



Cryptogamia. 



Magnified. 



Marsileaieoe. 



Natural size- 



Lycopodeaces 



The fourth order is MARSILEACE.S, containing 

 four genera. These are very inconspicuous plants, 

 springing up on moist ground among moss or grass, 

 having the appearance of tufts of small quills; 

 others bear little round heads ; hence they are called 

 pillwort. 



The fifth order is Musci, containing a great many 

 genera and species. These flourish only in cold 

 northern countries, and in shady damp situations. 

 Bogs and moist ground are covered with them, form- 

 ing a soft and compact carpet. They rank in the 

 lowest order of vegetation, and serve for a protection 

 or food for larger plants. 



The sixth order is HEPATIC.S, consisting of small 

 creeping inconspicuous plants, having their leaves 

 imbricated on each other, and quite distinct from the 

 lichens, which they in some degree resemble. One 

 of the genera, the jungermannia, is the most common 



