430 WILLIS : MORPHOLOGY OF THE PODOSTEMAOEÆ 
that of the vegetative organs. Perhaps in these cases, the 
dorsiventrality of the vegetative organs being greater, the 
gynæceiim comes under its influence at an earlier stage in 
the development at the growing point of the secondary 
shoot. By a still further increase of the dorsiventrality 
we come to Farmeria indica, in which the interior of the 
fruit for the flrst time shows extreme vertical asymmetry, 
the lower loculus being aborted, while the placenta is 
developed chiefly at the distal end. In this form, too, for 
the first time, we find a reduction of the number of seeds to 
four without any intermediate stages showing in any other 
species, and a corresponding increase in their size. As 
however they are still shed upon the rocks, it is not easy to 
see if this is any advantage to them, or whether it is only 
another expression of the increasing dorsiventrality ; but in 
the next species, Farmeria metzgerioides, we see the (so to 
speak) obvious next step taken, and the fruit, now dorsiven- 
tral to the extreme degree, remaining closed and sessile 
among the bracts, which thus hold the two seeds in position 
for germination in situ upon the rock when the water rises. 
Here again, then, the dorsiventrality seems impressed 
upon the gynæceum and fruit quite apart from any 
consideration of direct advantage to the fruit or to the 
performance of its functions. In Podostemon the dorsi- 
ventrality is still slight, it increases through the series of 
Hydrobryums, and at last affects the interior of the fruit in 
one of the Farmerias, but without being of any apparent 
advantage. Then suddenly, we come upon Farmeria 
metzgerioides, in which, so to express it, the plant has been 
able at last to make a good use of the phenomenon. 
The Seedlings. 
It is not necessary to add much to what has already been 
said about these. We now have a general knowledge of the 
seedlings of Lawia, Dicræa, Podostemon subulatus, two 
species of Hydrobryum, and one of Farmeria, besides a 
