92 CHARACEiE. 



substances contained in the vegetable membranes which are 

 related to the pollen of the male organ." 



" These chemical facts should be in harmony with the ob- 

 servations of ]M. Meyen and those of M. Brongniart upon the 

 spontaneous movements of little bodies enclosed in the pollen. 

 (Ann. des Sc. Nat., Nov. et Dec. 1838.) The particles of 

 Brown are found in my experiments to have an azotized 

 quaternary composition." 



The monospermic grain is composed chiefly, as was first 

 indicated by Raspail, of farina. 



The affinities of the order Characecs, are by no means 

 striking or satisfactorily determined. In being composed of 

 tubular cells, and in the disposition of these they exhibit a 

 relation to the Confervoid AlgcR generally, in the arrangement 

 of their branches in whorls, and in the circumstance of the 

 primary being crusted with other secondary and descending 

 cells, they manifest a relationship with the Batrachosperms 

 in particular. In their organs of reproduction, and in cer- 

 tain other respects, they bear some resemblance to the Equi- 

 seta, I know not how exact however. The Cliaracece are not 

 the only order of freshwater Algce possessing double organs 

 of reproduction : as, for examj)le, Vaucheria. Linnaius first 

 referred the CharacecB to the Cryptogamia, but subsequently, 

 regarding the globules as stamens and the nucules as pistils, 

 he removed them to Monoecia Monandria amongst flowering 

 plants. 



The Cliaracece, are almost universally distributed : they are 

 found abundantly both in fresh and stagnant waters, in all parts 

 of the world. They form an important link in the economy 

 of Nature, in life purifying by the liberation of oxygen during 

 respiration, the impure and almost pestilential waters in which 

 they are frequently and especially encountered, and in death 

 yielding by their decomposition elements which impart fer- 

 tility to the soil, and render it fit for the growth and nourish- 

 ment of plants of an order higher in the scale of organization 

 than themselves, and of more direct utility to man, the destined 

 recipient of all Nature's bounties, and for whose benefit every 

 natural contrivance directly tends. Let this thought impress 



