Gnetum Gnemon , with Notes on Gnetum funiculctre . 47 
tube is closed throughout this narrow region by the ingrowth of fairly 
regular epidermal cells with strongly lignified walls. 
The middle covering is much more differentiated, and except just 
at its apex is now fused throughout with the outer covering, as in G. scan- 
dens } In its expanded portions there are four large masses of lignified 
Text-fig. 4. G. funicular e. Cross-section of apex of seed, showing two bands of fibres in outer 
covering (c),4-lobed stony layer (j/) of middle covering (o), and lignified micropylar tube (;///). 
fibres (Text-fig. 4) which, lower down, pass into a heavily lignified layer 
composed of numerous horizontal fibres and a sort of indefinite palisade 
layer of fibres elongated at right angles to these; the outer layers are 
pa renchy matous. 
The fibres in the inner integument have not much, if at all, increased 
in number, but the outer covering is very fibrous in this seed, not succulent 
as in G. Gnemon. 
Comparative Summary of the Seeds of Four Species of Gnetum. 
The seeds of G. Gnemon are by far the most interesting of the four 
species I have seen, because of the complex arrangement for the closure of 
the micropyle. In the mature seed the canal of the micropylar tube is not 
only closed by the ingrowth of the epidermal cells, and by pressure due to the 
great increase in thickness of its wall, but the tube itself is also firmly fused 
to the outer covering. An upwardly directed flange, covered with cork 
which protects its delicate tissues, and a downwardly directed flange also 
fused to the outer covering, complete the solid stopper-like arrangement. 
Just above this lower flange the micropylar tube is broken across, and the 
papillate cells, which in the earlier stages fill up the cavity of the lower part 
1 Thoday, 1911 , p. 1118. 
