Fig. 12. 



mal direction by the growth of the main stem. The unrestricted 

 growth of the true plant has now commenced and the plant at this 

 point has the appearance of Fig. 1 7 (taken from A. de Bary, repre- 

 senting the germination of Ch. crinita), 

 "p," the main protonema; "p'p','' ac- 

 cessory and undeveloping protone- 

 mata, which sometimes arise; "s," the 

 stem-node, with unequally developed 

 leaves; the real protonema seems like 

 one of these leaves ; above this node 

 the true plant first appears and hairs 

 are developed on its first internode ; 

 "s'," imperfectly developed nodes of the accessory protonemata. 

 In perennial species (Ch. fragilis, Ch. gymnopus vars., etc.), 

 shoots arise from old plants (second generation), which 

 closely resemble the sprouts of the first generation (pro- 

 tonema). Old root- and stem-nodes of perennial species 

 swell and become filled with nourishment (starch prin- 

 cipally), and from these nodes new shoots arise, as from 

 the seed; these shoots are called caulescent protonemata ; 

 they develop root- and stem-nodes and behave quite like the true pro- 

 embryo. Pringsheim (1. c.) has studied these structures 

 with special care. 



'The first shoot of the fully developed plant is fre- 

 quently not the only one which rises from the verticil of 

 the protonema; in Tolypella there are so many that the 

 verticil of the protonema becomes the starting point of 

 a whole bundle of shoots of varying sizes and ages. In N. 

 syncarpa (Europe) these adventitious shoots rise not from 

 the stem-, but from the root-node; this swells to the size 

 even of a pea, and sends numerous roots downward and 

 shoots (as many as fifty) upward. Some of these incline 

 downward and form other swellings with roots and 

 shoots (caulescent protonemata). In Chara aspera, 

 however, the protonema-verticil remains undeveloped, 



producing neither leaves nor shoots, and the shoot of 

 the second generation arises from the root-node. " (A. 

 Braun.) 



The development of the stem, with its nodes, leaves 

 and various appendages, has been most thoroughly 

 studied by Prof. Braun, to whose writings, especially to "Ueber die 

 Richtungs-vorhaeltnisse der Saft-stroeme in den Zellen der Characeen, 



Fig. 14. 



