CARPOSPORE.E. 



297 



further divisions take place, till the ' apex of the pro-embryo ' which proceeds from 

 kt consists of a row of from three to six cells. Beneath the apex of the pro-embryo 

 |(Fig. 196, C, a, b) the tube swells, and the distended part becomes separated by 

 fa septum as a cell, which Pringsheim calls the * bud-rudiment,' (Fig. 196, C, including 

 the parts from "v to d). This cell is now divided by two oblique walls into three 

 ;ells, the middle one of which (q) lengthens into a tube (like an internode), while the 

 ipper and lower ones remain short. Out of the lower cell is afterwards formed a 

 'oot-producing leafless node (Fig. 196. d, and Fig. 191, d), while the upper one, which 

 [lies between the apex of the pro-embryo a b and the elongated cell q becomes the 

 [axis of the new generation. It becomes arched on one side outwards, and divides in 

 succession into the cells J, //, ///, and ij. Each of the cells /, //, and /// becomes 

 f transformed by divisions into a disc of cells or transitional node, three of which thus 

 i stand over one another with- 

 [out intermediate internodes. 

 JTheir lateral cells grow right 

 ind left, and form imperfect 

 leaves of different lengths. The 

 :ell which lies outermost (Fig. 

 [96, C, n}) now begins to un- 

 lergo a series of divisions, 

 :orresponding to those of a 

 normal leaf-bearing shoot. It 

 is, in fact, the apical cell of 

 the sexual leaf-bearing plant 

 which arises from the pro- 

 embryo. The displacement 

 indicated in Fig. 196, C, sub- 

 sequently causes the apex of 

 the pro-embryo to be pushed 

 to one side; and since this 

 apex has the appearance of a 

 simple leaf uncovered by cor- 

 tex, the further development 

 of the lateral leaves which 

 spring from the cells /, //, 

 and 7J/, brings about an ap- 

 pearance as if these different 

 leaves together formed a whorl ; 

 and the bud of the lateral 

 shoot thus comes to stand 

 apparently in the centre of 

 this pseudo-whorl (Fig. 196, 

 A), If the structure which 



springs from the germinating spore is now compared with the pro-embryonic branch, 

 the perfect homology cannot fail to be observed which Pringsheim pointed out in 

 the parts that will be found indicated by the same letters in Figs. 191 and 196; 

 but the pro-embryo of the spore has in addition a small node at the opening of the 

 spore from which a rhizoid, sometimes called the primary root of Chara, springs 

 (Fig. 191, w'). 



The Antheridia and Carpogonia are always borne by the leaves. An antheridium 

 is in all cases the metamorphosed terminal segment of a leaf or of a leaflet, and the 

 carpogonium, in the monoecious species, arises close beside the antheridium from the 

 basal node of the same leaflet [Chara) or from the last node of the leaf bearing a 

 terminal antheridium {Nitella) ; hence in the monoecious Niteliae the carpogonia are 



Fig. \()-].— Chara fragilts. A middle part of a leaf b with an antlicridium 

 a and a carpogonium 5, c its crown ; |3 sterile lateral leaflet ; |3' large leaflets 

 by the side of the carpogonium ; ^" the bracteoles, spinging from the basal 

 node of the carpogonium ( X about 50). B a young antheridium a with a still 

 younger carpogonium SK; w the nodal cell of the leaf, u the uniting-cell 

 between it and the basal node of the antheridium ; / cavity of the internode 

 of the leaf; br cortical cells of the leaf ( X 350) {cf. Fig. 203). 



