CHARACE.^. 



291 



peripheral cells, as in sterile leaflets, but five ; an upper odd one which is first formed, 

 two lateral ones which follow, and two lower ones which are formed last of all. Of 

 these five cells only the two lower ones are developed into cells which form the cortex 

 (of the leaves), the upper one, wanting in the sterile basal nodes, is the mother-cell of 

 the nucule • but the two lateral ones are developed into leaflets which stand laterally 

 between the globule and nucule {cf. Fig. 204, /3"); these latter Braun calls Bracteoles. 

 The mother-cell of the nucule now grows out of the axil of the globule, and divides 



FIG. ij^i.—Charafra^ilis; A lower part of a fertile leaf, a lateral bud springing from its axil ; B lower part of a sterile 

 leaf without an axillary shoot (in longitudinal section). 



itself by a septum into an upper outer terminal cell and a segment which in its turn is 

 broken up into two discs by a w^all paraflel to the previous one (Fig. 210, A, SK). The 

 lower cell does not divide any further, it forms the concealed pedicel of the nucule, 

 and corresponds to the first internode of a branch ; but the upper one has the character 

 of a nodal cell ; it is divided by tangential walls into a zone of five outer and one inner 

 cell (SK') ; the former are the rudiments of the enveloping tubes, which are therefore 

 morphologically leaves. 



u 2 



