38 



BRITl SH OHAEOPH YTA. 



vegetative reproduction, embryonic and pro-embryonic 

 branches. When first noticed, before their function 

 was ascertained, they were assumed to be of calcareous 

 substance. The presence of bulbils has been satisfac- 

 torily established in the case of comparatively few 

 species, but upon further investigation these processes 

 will probably be found to occur in many others. In 

 collecting Charophytes the rooting portion is often 

 neglected, moreover bulbils are apparently produced 

 only under certain conditions of growth. Those who 

 have the opportunity of following the growth of any 



Fia. 11. Root-bulbils (spherical type) of Char a aspera (after 

 Giesenhagen). i. Root-node showing double-footed joint with 

 three bulbils, two nearly spherical, and one cylindrical ; also some 

 rhizoids ( x c. 11). ii. Root-node bearing one spherical bulbil, with 

 young plants arising from nodes at basal and distal ends ( x c. 13). 



Charophyte throughout the year either in its natural 

 condition or in cultivation will do well to examine the 

 roots from time to time to ascertain if bulbils are 

 being produced. 



There are three distinct types of bulbil : (1) con- 

 sisting mainly of a large nearly spherical cell (Fig. 11), 



(2) more or less amorphous, consisting of an agglo- 

 meration of numerous small cells (Figs. 12 and 13), 



(3) star-shaped, being modified branchlet - whorls 

 (Fig. 15). 



The first type of bulbil, those of spherical form, are 

 found among British species, in Ghara aspera, 



