ss 



CHA RACEME. 



walls ; and the globule now consists of four lower and four upper octants of a sphere. 

 Contraction by glycerine clearly shows that each of these divisions of the protoplasmic 

 body is completely effected before the appearance of the cellulose-wall (Fig. 207, 5); 

 the second division even takes place before the wall has arisen between the two first- 

 formed halves ; and the four quadrants may be made to contract without any wall being 



visible between them. In Fig. 207, B, the third 

 division has also taken place, the second ver- 

 tical wall is already formed, and the two quad- 

 rants there visible are already divided ; but no 

 horizontal wall has yet appeared. In Fig. 207, u4, 

 a, are shown the eight octants in perspective 

 together with their nuclei. Each octant now 

 breaks up first of all into an outer and an inner 

 cell (Fig, 207, C) ; the latter is again divided in 

 all the eight octants (D), so that each octant 

 now consists of an inner, a middle, and an outer 

 cell (Z), /, m, e). Up to this time the globe re- 

 mains solid, and all the cells lie close to one 

 another ; but now commences an unequal 

 growth, and w^ith this the formation of inter- 

 cellular spaces (Fig. 208). The eight outer 

 cells (£■) are the young shields, the side-walls of 

 which show even at an earlier period the radial 

 infolding already mentioned. They grow more 

 strongly in a tangential direction than the inner 

 cells, the outside of the globe increasing more 

 rapidly than the inside ; the middle cells (w), 

 which form the manubria, remain attached to 

 the centres of the shields, but are separated 

 from one another by the tangential growth of 

 the shields ; they grow slowly in the radial direction ; the innermost cell / of each octant 

 is rounded off and becomes the head. 



The celiy in Fig. 207, D, now also grows quickly, and forces itself between the four 

 low^er shields into the interior of tlie ^lobe ; it becomes the flask-shaped cell, upon the 

 apex of w^hich rest the eight heads. In Fig. 208 this condition of the globule is shown 

 in longitudinal section ; where the walls of the heads bound the intercellular spaces 

 which have now been formed and are filled with fJuid ; they put out branches (c) 

 which become septate, and again ramify ; and these branches elongate by apical growth 

 and also become septate. The lowermost cells swell up into a roundish shape, and 

 form the secondary heads, upon which stand the whip-shaped filaments, consisting of 

 the discoid cells which are the mother-cells of the antherozoids. (Compare Fig. 208 with 

 Fig. 205, B.) 



The globules of Chara fragilis are produced by metamorphosis of those leaflets which 

 form the innermost row on a leaf, and in fact, as is shown in Fig. 210, the develop- 

 ment advances downwards to the primary leaf. The succession of cells and the mode 

 of growth show no noteworthy difl^eren-ces from those of Nitella ; the flask-shaped 

 pedicel is here placed on a small cell wedded in between the cortical cells, the central 

 cell of the basal node of the leaflet, which Braun asserts to be present also in sterile 

 leaves, where however I have not succeeded in finding it. 



Antherozoids. The whip-shaped filaments in which the antherozoids arise, do not 

 grow merely at their apex, but have also an intercalary growth. This is shown by the 

 elongated cells in the middle of young filaments, each with two nuclei, between which no 

 division-wall has yet been formed (Fig. 205, C). The longer the filaments become, the 

 more numerous are their divisions, until at length the individual cells have the appearance 



Fig. 208. — Antheridium o{ Nitellaflexilis in a furtlier 

 stage of development (X about 500). 



