the internodal cell and so meet cortical cells from the node above 

 and below. The cortical cells in their development themselves cut 

 off small node cells. These show as small round units in the series; 

 often they are spiniferous. From the node cells of the corticating 

 cells secondary corticals may be cut off and grow down alongside 

 the primary elements. These may be more prominent than the 

 primary, or less so, a specific character of taxonomic value. Some- 

 times there are two such cells cut off, one on either side of the 

 primary cortical cell. The results of the behavior of the node cells 

 of the cortical elements are then: 1. The node cells may not produce 

 laterals and the cortical cells are rather large and equal in number 

 to the leaves, which are borne at the node of the stem. This 

 condition is known as haplostichous cortication. 2. If the node cell 

 of the cortical series cuts off one lateral so that the cortex is com- 

 posed of alternating primary and secondary cells the condition is 

 known as diplostichous, and there are twice as many cortical cells 

 as there are leaves at the stem node. 3. The node cells of the cortical 

 series may give rise to two laterals, one on either side, so that in 

 the circumference of the stem the primary cells alternate with two 

 secondary cortical cells, and there are three times as many cortical 

 cells as there are leaves in the whorl at the stem node. This condi- 

 tion is known as triplostichous. There are irregularities in these plans 

 of arrangement, so that it is often necessary to examine many stem 

 sections to obtain the necessary information for taxonomic consid- 

 erations. Rarely the stems are ecorticate. 



In most forms, besides bearing a whorl of leaves, the stem node 

 is encircled by a single or double row of spine-like cells, the 

 stipulodes. 



The nodes of the leaves may be smooth or they may bear leaflets 

 or bracts (bracteoles). Some of these may be mere papillae, whereas 

 others at the same node may be much elongated, especially at fertile 

 nodes where there are usually 2 or 4 long bracts about the oogonium. 

 The last 1 to 4 cells of the leaves may be ecorticate and the general 

 foi-m and arrangement of these cells at the tip, and the lateral 

 elements given off just below the uncorticated cells at the end of 

 the leaves are characteristics which are of taxonomic value also. 



There are both monoecious and dioecious species. In the former 

 condition the oogonia are always borne above the antheridia, devel- 

 oping, however, from the same initial cell in the node of the 

 branchlet. 



Only the more conspicuous species of Chara were collected, and 

 in the present treatment I have included one which has been 

 previously reported. Hence only a few of the many forms which 



[335] 



