368 
Notes . 
may be attached directly by a spreading disc-like group of haptophores, borne on 
a short stout rhizoid, or they may extend for some distance horizontally, below the 
surface of the woody matrix, and then may produce assimilating branches as well as 
rhizoid-bearing cells. It is very difficult to demonstrate the behaviour of this rhizome- 
like basal region owing to the fragile nature of the material. 
The rhizoids are rarely septate, and appear to be enucleate. Ends of one or two 
chromatophores, however, elongate, and extend into the first-formed protuberance. 
Fig. 2. Spirogyra adnata (?), showing basal cell which had attached itself to a glass dish by 
means of three rhizoids, into each of which chromatophores have penetrated. 
These appear to keep pace for a time with the growth of the tube, but they may 
fragment into small pieces, which may be seen either isolated, or connected only by 
an attenuated thread of granules, at intervals along the length of the tubes : these 
fragmented pieces appear to always contain at least one pyrenoid. 
The rhizoids may be formed either as lateral or terminal protuberances ; and in 
cells with lamellose walls, the inner cellulose lining of the walls appears to break 
through the outer gelatinous layers. The initial outgrowth may either branch and 
give rise to other more slender tubes (Fig. 2), or it may at once form a bunch 
of outspread haptophores with thick gelatinous walls (Fig. 1 b). It seems 
probable that, as in the cases described by Borge, the rhizoids are formed primarily 
as the result of contact stimulus, but further observations are needed on this and other 
points. 
E. M. DELE. 
Westfield College Laboratory 
