Richards: Ceramothamnion codii 259 



formed wall. These are the young nodal cells and their 

 formation does not appear to be always simultaneous, nor when 

 successive, in any particular order. The next step in the forma- 



* 



tion of the node is the rounding off of these cells and their trans- 

 verse division. There are now two rows of cells, which subse- 

 quently may become by division two double rows of eight cells 

 each, or sixteen cells in all at the nodes. Sometimes but one of 

 the original two rows divides again transversely, in which case 

 there will be but twelve cells in the node, disposed in one single 

 and one double row. But in the older parts of the filaments the 

 rows ultimately become displaced, owing to irregular divisions of 

 some of the cells. 



The internodal cells develop by enlargement in all directions, 

 particularly in length, and the original tapering end caused by the 

 obliquely formed walls of the nodal cells increases rather than 

 diminishes. It is this constriction between the internodes which 

 is, as has before been said, closely packed with the nodal cells, 

 the outline of the filament being almost straight and continuous. 

 The erect branches arise from the nodes of the procumbent fila- 



ments, 



ppe 



function of the apical cell of the branch. Each node may pro- 

 duce its branch, but no cases were observed where more than one 



¥ 



arose from a single node (Fig. i). The rhizoids which grow into 

 the tissue of the Codiutn also originate from nodal cells of the 

 main filament, but from the under side of course, and make their 

 way downwards into the tissue of the host. They are colorless, 

 or almost so, and often sparingly dichotomous, exhibiting no 

 especial peculiarities. Branching of the upright filaments is seen 

 only in connection with the formation of certain forms of the fruit 



which will be considered later. • 



Some of the material collected was found to be provided with 

 hairs which arise from the nodal cells. While usually short (Fig. 

 4) they are sometimes prolonged as in Fig. 5. The short hairs 

 cannot be considered simply younger ones for they are often 

 found on fully matured portions of the filament. Their contents 

 indicate that they are simply sterile hairs, as it is very scanty and 

 gathers at the end in the way common among such organs. 

 They were also found on material in all conditions of fructification. 



