392 WILLIS : MORPHOLOGY OF THE PODOSTEMxlCBÆ 
two cases marked g have grown outwards to some dis- 
tance. From near one end there springs the trumpet-shaped 
organ which is flattened out at the end, and appears to 
have been attached to the rock (the specimen was obtained 
in the usual way by groping in deep water) ; its margin 
is like that of a normal thallus and appears to have grown 
in a similar way. On the far side are four pitcher-like 
organs, a, h, c, springing from the margin, in different 
stages of development, and on them endogenous shoots 
(s.s.) are forming, somewhat as in Dicræa elongata. These 
pitchers are hollow at the outer ends for some depth. The 
whole is of interest as showing once again the almost un- 
limited plasticity of the thallus in these plants. 
Rejuvenescence , — As in most of the other species, so here, 
the thallus, so long as alive, seems to have an almost unlimited 
capacity for the production of new growing points and the 
renewal of growth after exposure to air or other injury. 
The new growing point is formed endogenously behind the 
injured portion, and grows out from it in the usual scallop- 
shell form (PI. XXXVI., figs. 3, 4). Exactly how long the 
thallus can stand exposure without losing all capacity for 
regeneration is uncertain, but 1 have found several cases in 
this as in other species, where it appeared to have survived 
several months after being exposed by the fall of the water 
in .January. When the flowers are ready to open the thallus 
and stalks are crammed with reserves, especially starch, and 
hence the ripening of the fruit is very rapidly carried out 
after fertilization ; but all the starch is not thus used up, 
and by means of Avhat is lefc the plant is able to regenerate 
its thallus if placed under water once more. 
With regard to Rodostemon Gardneri^ Harv. MS., a few 
notes must be made. Thwaites’ original description is as 
follows : “ caule simplici, terete, glabro,foliis plurimis capil- 
laceis coronato. C. P. 2,989. Hab. on the membranaceous 
rhizomes of Hydrobryum olivaceum. Tub In a rapid 
