324 



formed externally of a reticulated transparent membrane, containing, in the 

 midst of a mucilaginous fluid, certain white transparent filaments, and some 

 other cylindrical bodies, closed at one end, and appearing to open at the other. 

 These latter are filled with the red matter to which the tubercles owe their 

 colour, and which disappears readily and long before the maturity of the 

 nucule." The account of the globule by Agardh is at variance with both these. 

 " Their surface," he remarks, " is hyaline, or colourless ; under this membrane 

 is observed a red and reticulated or cellular globe, which has not, however, 

 always such an appearance ; often, instead of this reticulated aspect, the globe 

 is colourless, but marked by rosettes or stars, the rays of which are red or lance- 

 olate. In the figures given by authors, one finds sometimes one of these forms, 

 sometimes the other. I have myself found them both on the same species ; 

 and T am disposed to believe that the last state is the true kernel of the 

 globule, concealed under the reticulated scale. (When the globule is veiy 

 ripe, one may often succeed, by means of a slight degree of pressure, in sepa- 

 rating it into several valves, as is very well shown in Wallroth's figures, tab. 2. 

 f. 3. and tab.»5. These valves are rayed, and no doubt answer to the stars, of 

 which mention has been made.) The kernel contains some very singular fila- 

 ments ; they are simple (T once thought I saw them forked,) curved and inter- 

 laced, transparent and colourless, with transvere striae, parallel and closely 

 packed, as in an Oscillatoria or Nostoc ; but what is very remarkable, they 

 are attached, several together, to a particular organ formed like a bell, which 

 is itself also colourless, but filled with a red pigment. This bell, to the 

 base of which on the outside they are fixed, differs a little in form in different 

 species. It is slender and long in Chara vulgaris, thicker in C. firma, shorter 

 in C. delicatula, and shorter still in C. collabens. I have not succeeded in de^ 

 termining the exact position of these bells in the kernel. I have often thought 

 they were the same thing as the rays of the rosettes or stars upon the globule 

 above mentioned ; whence it would follow that they are placed near the sur- 

 face, while the filaments have a direction towards the centre. The bells are 

 not numerous ; they often separate from the filaments, and readily part with 

 their pigment, which renders it difficult to observe them, and has caused them 

 to be overlooked." ThaJ these globules, whatever their nature may be, have 

 no sort of analogy in structure with anthers, is clear from these descriptions, 

 whichever may be eventually admitted. Wallroth, indeed, says he has sown 

 them, and that they have germinated ; but this observation requires to be 

 verified. 



It does not appear from the preceding descriptions that Chara has a marked 

 affinity to any other plants. I incline to the opinion of those who consider it 

 near Confervae, chiefly on account of the organization of the stems ; for it 

 does not seem that the reproductive organs of flowerless plants aie of the 

 same degree of importance in deciding affinities as the fructification of flower- 

 ing plants. Its total want of vascular system renders it impossible to adopt 

 the opinion of those who would place it near Ferns next to Marsileaceas, and 

 the regularity with which all the parts are formed round a common axis renders 

 it equally impossible to refer it absolutely co the leafless section. I therefore 

 place it on the limits of the latter, among Muscoideee. 



There are two other points deserving of attention in Characere : 1st the cal- 

 careous incrustation of some species ; and 2dly, the visible and rapid motion of 

 the sap in the articulations of the stem. 



Of the two genera, Nitella is transparent and free from all foreign matter ; 

 but Chara contains, on the outside of its central tube, a thick layer of calca^ 

 reous matter, which renders it opaque. This incrustation appears, from the 

 observations of Dr. Greville {Fl. Edin. 281), not to be a deposit upon the out- 

 side, and of an adventitious nature, but the result of some peculiar economy in 



