elvi Proceedings of the Asiatic Society of Bengal. [N.S., XV, 
have hardly given rise to the Pteridophytes—but on the con- 
trary may have been derived from them. The writer has tried 
to establish certain principles of that reduction as well as the 
paths along which it has proceeded from the study of the 
Indian forms. It is curious to note that Professor Goebel was 
led to the idea of reduction in the Liverwo rts from his study 
in 
been lost since then, until it was discovered accidentally by 
Goebel and investigated by him fully in 1910. 
The principles mentioned above are best seen in the 
Marchantiales, perhaps, because _ plants have been more 
thoroughly studied by the wri but similar principles 
also discernible in the J SS and the hip seecgee 
I will take the genus Dumortiera first as it illustrates very 
clearly the process of reduction and some other phenomena. 
carum) three species and a fourth was described by Campbell 
from Borneo afew months ago. (Annal of Botany, July 1918.) 
_Of the first three, two, D. hirsuta and D. trichocephala, have 
been known from India and other parts of the world, but the 
third, D. velutina, has been said to be endemic only in Sumatra 
and Java. It has, however, been found by the writer to be 
jeeling, including some parts of the middle range of the main 
chain, e.g. the Chamba valley. It may incidentally be men- 
tioned here that arguments from the distribution of some 
genera and species may not be very safe in the present state 
of knowledge. It should be mentioned however that the Hima- 
layan specimens differ slightly from the type, especially in 
their densely setose male receptacles. Probably this plant has 
n pains to be D. hirsuta in the Himalayas. 
with its aquatic habit of an entire absence of air-chambers in 
the mature thallus, the presence of such chambers being an 
important character of the Marchantiales. The air-chambers 
come fname later. Tt i is Fate eres that the process in 
this case is that of reduction. 
The third species shows no trace of air-chambers even at 
the © 3p the reduction having gone further. There can be no 
of the higher forms of the group. In D. velutina these papil- 
late cells are met with all over the thallus even in the mature 
