610 



E O T A N Y. 



often growing among, and sometimes extirpating 1 , the 

 grasses of moist meadows. 



The sixth order is HEPATIC.* or liverwort moss, 

 containing six genera, and ninety-four species. They 

 are like some of the foregoing small creeping plants, 

 and inhabiting the same damp and cold places. They 

 are, however, very different in structure from the 

 other genera of this class. 



The second class of cellulares is called Aphyllts, 

 because they are entirely destitute of leaves or leaf- 

 like expansions. This class has three divisions. The 

 first is ALG^E, containing seventy-nine genera, and 

 four hundred and fifty-three species. Among the 

 algae, the simplest forms of vegetation are to be found, 

 and also some gigantic sea-weeds rising from great 

 depths of the sea. Some of hair-like structure have 

 a spontaneous motion like worms ; some require a 

 microscope to be seen, and of very different character 

 as to duration, perennial, annual, or ephemeral. Some 

 of the sea species are edible, their flavour being mild 

 and rather grateful. 



The second division are the LICHENES, containing 

 thirty-five genera, and four hundred and twelve 

 species. These are the plants which cause the wea- 

 ther-stains on old buildings ; they creep on the naked 

 rocks, and attach themselves to the trunks and 

 branches of trees. Some of them are used in diet 

 and in medicine, and several by the dyer. They 

 flourish most in northern climates, and for some 

 animals answer the purposes of forage. 



The third and last division of the class aphyllse is 

 the FUNGI, which is by far the most numerous of all. 

 Of these there are one hundred and fifty-nine genera, 

 and one thousand one hundred and fifty-seven species. 

 The mushroom is one of the best known genera, and 

 lends its name to many that do not belong to the 

 family. The toads' stool and other boleti are often 

 mistaken for mushrooms by ignorant people, who not 

 unfrequently use them at the peril of their lives. 

 The mould on cheese and stale bread are fungi ; so 

 is the mildew on trees, and the rust on corn. Though 

 so many of this division have been discovered, it is 

 more than probable that hundreds remain unnoticed 

 and unknown. 



As the figures of the classes a'nd orders of the second 

 grand division CELLULARES are all represented on the 

 plate, they are omitted under their respective titles 

 here, being easily referred to while the descriptions 

 are read. 



The foregoing is a very brief sketch of the Jus- 

 sieuan system as improved by later writers. The 

 descriptions of the divisions, classes, subdivisions, 

 and subclasses, are all intentionally brief, because 

 these, together with each order of the subclasses, have 

 been or will be particularly noticed as they occur 

 alphabetically in the body of this division of the 

 Cyclopaedia. Another reason for the brevity alluded 

 to is the pictorial illustrations of Jussieu's divisions 

 and subdivisions, which will be found at the end of 

 this article, and which, when compared with the ex- 

 planations of the titles of each subclass, cannot fail to 

 convey a pretty clear idea of the grand features of 

 this popular and nearly universally received system. 



As there are many other terms employed in the 

 Jussieuan system of botany that have not been used 

 in the foregoing sketch, it may be necessary in this 

 place, while giving a. kind of summary of the whole, 

 to notice them. 



It has ajrcady been observed that Jussieu divides 



the vegetable kingdom into two grand and well de- 

 fined parts, namely, VASCULARES and CELHILARES. 

 The first is also called Cotyledonece, and the second is 

 also called Acotylcdonece for reasons assigned under 

 those titles. Vasculares are, moreover, called Pha- 

 nerogamia or Plucnogamia, because they have visible 

 flowers ; and cellulares are called Cryptogamia, be- 

 cause they have no visible flowers. 



Germination of Dicotyledons. 



VASCULARES are separated into two classes called 

 Dicotyledons or JExogenes, and Monocotyledons or 

 Endogenes, significant of their manner of growth ; 

 the former rising with two seed-leaves, and increasing 

 by additions on the outside ; the latter rising with 

 one seed-leaf, and increasing by additions in the 

 inside of their stems. 



These greater features of the system being first 

 fixed, the author next proceeded to determine what 

 should be the signs for subclassing the vast number 

 of plants then known to botanists. This subclassing 

 was necessary on two accounts, viz., to follow nature 

 in forming congenial groups, and to facilitate the 

 study of the science. In doing this he was naturally 

 led to the consideration of the structure of the flowers. 

 Here he found that a very great majority had the 

 two outer coats, namely, the calyx and corolla, per- 

 fectly distinct ; and another considerable portion of 

 flowers in which these members were united. This 

 difference of structure afforded very obvious marks 

 on which to found two subdivisions of the first class. 

 These subdivisions are Dichlamydece and Monochla- 

 mydecB. The former containing three subclasses 

 founded on the situation of the stamens, as whether 

 seated below the pistillum, upon the calyx, or upon 

 the corolla ; the latter having no subclass, the union 

 of the calyx and corolla being deemed a sufficient 

 distinction of monochlamydous plants. Thus the 

 greater number of conspicuous flowering plants were 

 disposed of; and those which remained, forming the 

 second class monocotyledoneae, were easily distin- 

 guishable by the circumstances of rising with one 

 cotyledon only, and from the very different structure 

 of their leaves and stems. 



Dichlamydese ; calyx and corolla distinct. 



Thus were the phosnogamous or flowering plants 

 arranged ; and it only remained to classify the cellu- 

 lares or atotyledoneae in some other way than by 

 their flowers, which were unobvious or unknown. 



