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Affinities. The two genera of which this little order is composed are 

 among the most obscure of the vegetable kingdom, in regard to the nature 

 of their reproductive organs ; and accordingly we find them, under the com- 

 mon name of Chara, placed by Linnseus among Cryptogamous plants near 

 Lichens ; then referred by the same author to Phsenogamous plants, in 

 Moncecia Monandria ; retained by Jussieu and Decandolle among Naiades, 

 by Mr. Brown at the end of Hydrocharidese, and by Leman in Haloragese ; 

 referred to Confervte by Von Martins, Agardh, and Wall roth ; and finally 

 admitted as a distinct order, upon the proposition of Richard, by Kunth, 

 Decandolle, Adolphe Brongniait, Greville, Hooker, and others. Such being 

 the uncertainty about the place of these plants, it will be useful to give 

 rather a detailed account of their structure, in which I avail myself chiefly 

 of Ad. Brongniart's remarks in the place above referred to, and of Agardh's 

 observations in the A)in. dcs Sciences, 4. 61. I have not seen Professor 

 Nees v. Esenbeck's monograph of Characeag in the Transactions of the 

 Rafisbon Society, quoted by the latter author. 



Characeseare aquatic plants, found in stagnant fresh or salt water ; always 

 submersed, giving out a fetid odour, and having a dull greenish colour. Their 

 stems are regularly branched, brittle, and surrounded here and there by 

 whorls of smaller branches. In Nitella the stem consists of a single trans- 

 parent tube with transverse partitions, and, as Agardh remarks, so like the 

 tubes of some Algse, as to offer a strong proof of the afhnity of the orders. 

 In Chara, properly so called, there is, in addition to this tube, many other 

 external ones, much smaller, which only cease to cover the central tube 

 towards the extremities. In the axillse of the uppermost whorls of these 

 branchlets the organs of reproduction take their origin ; they are of two 

 kinds, one called the nucule, the other the globule; the former has been 

 supposed to be the pistillum, the latter the anther. 



The nucule is described by Dr. Greville as being " sessile, oval, solitary, 

 spirally striated, having a membranous covering, and the summit indistinctly 

 cleft into 5 segments ; the interior is filled with minute sporules." Fl. Edin. xvii. 

 This is the general opinion entertained of its structure. But Ad. Brongniart 

 describes it thus : — " Capsule unilocular, monospermous ; pericarp composed 

 of two envelopes; the outer membranous, transparent, very thin, terminated 

 at the upper end by 5 spreading teeth ; the inner hard, dry, opaque, formed of 

 5 narrow valves, twisted spirally." Diet. Class. 1. c. He founds his opinion 

 of the nucule containing but one germinating body upon the experiments of 

 M. Vaucher, of Geneva, who asceitained that if ripe nucules of Chara, which 

 have fallen naturally in the autumn, are kept through the winter in water, 

 they will germinate about the end of April ; at that time a little body pro- 

 trudes from the upper end between the 5 valves, and gradually gives birth 

 to one whorl of branches, which produce a second. Below these whorls the 

 stem swells, and little tufts of roots are emitted. The nucule adheres for a 

 long time to the base of the stem, even when the latter has itself begun to 

 fructify. Hence it is reasonable to conclude that the nucule is really mono- 

 spermous. M. Brongniart remarks, that it is true, when a fresh nucule 

 of Chara is cut across, an infinite number of little white grains are squeezed 

 out ; but if these were really all r(-j)roductiv/3 particles, how would they ever 

 find their way out of the nucule, which is indehiscent? he considers them 

 rather of the nature of all)unicn. And he is the more confirmed in his 

 opinion, because in Pilularia, the thectc of which also conttiin many similar 

 grains, but one plant is produced by each theca. Finally, Amici has de- 

 scribed {Ann. des Sc. 2.) the nucule in another way. He admits it to be 

 monospermous, but he considers the points of the 5 valves to be stigmata. 



