382 WILLIS : MORPHOLOGY OP THE PODOSTEMACEÆ 
In the Nilgiri form, and occasionally in the others, the 
simplicity of the construction is further masked by the 
curious way in which the thallus frequently crumples, as 
seen in the right-hand specimen in the plate, where the 
upper parts of the thallus are crumpled and ridged into 
a dense irregular mass. 
The flowers open at once after exposure, and shed their 
seeds upon the rocks in the usual way, where they may be 
retained in crevices of the rock or of the old thallus. 
Germination and Life History . — Germination takes place 
in April and May, when the Avater-level rises during the 
little monsoon. The first stage is much the same as in the 
species already described. The seed SAvells and bursts its 
coat, the hypocotyl emerging and bending downwards to 
touch the substratum, where it promptly becomes fastened 
by means of the usual rhizoids developed from its superficial 
cells. The basal portion usually enlarges slightly, and from 
it are almost immediately developed outgrowths — the thallus 
and haptera. The early stages of development are extremely 
interesting, and I much regret that I have not been able to 
obtain sufflcient material to follow out all the details. The 
seedlings are very minute, and grow in places where it is 
very hard to And them, and I have to consider myself very 
fortunate in having got so many as I have actually 
obtained. 
PI. XXXII., flg. 11, shows the earliest stage that I have 
seen, the seedling being. about 2\ mm. high, with two 
cotyledons developed, an erect hypocotyledonary axis as 
loDg as the cotyledons, and two small outgrowths at the base. 
In the specimen here shown one of these, the left-hand one, 
was certainly exogenous, the other, on the right, endogenous. 
It is often extremely difficult in these seedlings to make out 
whether a particular organ is exo- or endo-genous. Those 
cases where the organ is certainly exogenous are easy, for by 
aid of the microscope the surface cells can be traced from 
the stem to the lateral organ, cell fitting on to cell with no 
break of continuity ; there are, however, many cases where 
