24 Lang . — Prothalli of Ophioglossum pendulum 
the literature need be given here. The prothalli of Ophio- 
glossmn pendulum and Helm in tho s tacky s zeylanica 1 will first 
be described, so that comparison can be made on the basis of 
a knowledge of this stage in all three existing genera. The 
material on which the investigation of these prothalli has been 
made was obtained from the Barra wa Reserve Forest at Han- 
wella in the Western Province of Ceylon. The prothallus of 
O. pendulum was collected on a visit to this locality in October, 
1 900 : this was made in the company of Mr. F. Lewis, to whom 
I am indebted for great assistance in the search, and for the 
facts, regarding the peculiar conditions, which obtain in this 
low-lying forest. Those of Helminthostachys were collected in 
the beginning of the succeeding March, and the material 
which I obtained was supplemented by more than fifty pro- 
thalli obtained from the same locality by Mr. A. K. Coomara 
Swamy a few weeks later and kindly forwarded to me. I wish 
to express my thanks to Mr. Coomara Swamy for generously 
placing this large stock of material at my disposal for the 
purpose of this investigation : without it certain facts would 
have been missed and others could not have been investigated 
so fully. The large number of prothalli under observation has 
also removed doubts as to the characters noted being normal. 
I have further to thank my friend Mr. Willis, the Director of 
the Peradeniya Botanic Gardens, for much assistance in 
selecting localities in which to search for these prothalli. 
Ophioglossum pendulum. 
The sporophyte of this plant was frequently seen hanging 
from masses of epiphytic Ferns, its roots being embedded in 
the humus accumulated by the Ferns. It sometimes grows 
upon plants of Cycas or Phoenix , hanging from the stem 
below the crown of large leaves. A number of specimens, 
which grew on Asplenium nidus and Polypodium quercifolium , 
were carefully examined. In the humus collected by a mass 
of the latter Fern numerous prothalli were found. They were 
1 A preliminary statement on these prothalli has been published in the Proc. 
Roy. Soc., vol. lxviii, 1901, p. 405. 
