420 THANSAG'IION.S AND PIK 'CKKDINGS OF THE [Sess. LXViii. 



from the base of the preceding bulb to a greater or less 

 distance below. This process, which is quite like the 

 old rootstock, is smooth, and pale in colour, and in dried 

 specimens is sometimes seen to be loosely wrapped in 

 a membranous covering, evidently an exfoliation. This 

 downward extension of the plant's axis is an exact 

 counterpart of the rootstock above it, terminating like it 

 in the pro-bulb expansion, with the true bulb attached 

 to its under surfa* e. The close association of the two 

 structures appears to exist from an early stage in their 

 development, as shown in one plant in which the fourth 

 bulb-formation on its axis is seen of very small size at 

 the end of a process 2 mm. in length. In this case 

 the one is about as large as the other, namely, 1 mm. 

 in diameter, — although at a later stage the bulb will attain 

 larger dimensions. The brown scales of the true bulb are 

 quite distinct from the membrane of the rootstock, and 

 appear to be an exfoliation from its substance of annual 

 occurrence. As the downward budding process takes 

 place during the flowering period, resulting in the for- 

 mation of a reserve of nutriment for the plant during the 

 immediately following dry season, so we may assume as 

 highly probable that at an earlier period, when the winter 

 rains followed the long dry summer, the base of the root- 

 stock must send a shoot upwards to form the stem of 

 the plant that makes its appearance above ground in the 

 course of the winter. This pro-bulb, therefore, may be 

 regarded as containing the dormant bud, or buds, from 

 which the plant is annually renewed,- — these being the 

 homologues of those buds known as the winter buds or 

 hybernacula in the axils of the rosette-leaves of European 

 species of Broscra. It may be a nice point for consideration 

 whether the pro-bulb or the bulb is the really permanent 

 organ on which the plant depends for its annual regener- 

 ation. Unfortunately, direct observation of the earliest 

 stages of the growth of the new axis of the plant is difficult 

 of attainment, seeing that after the flowering season of the 

 bulbous species of Drosera is over all that was visible of 

 them above ground quickly disappears, and nothing to 

 indicate their presence can be detected till the new stem 

 appears above the surface in the i'ollowing spring. 



