190 
LE GOC : 
constant supply of male cones of Encephalartos and 
Macrozamia. 
Experiments were then carried out in order to obtain more 
positive and more definite information. Young megasporo- 
phylls at Peradeniya were screened off against pollen grains 
by means of muslin bags applied before the ovules were ripe 
for polHnation or were exposed to the action of the wind or 
of visiting insects. But any one who has tried the use of 
muslin bags in open places knows the practical difficulty of 
this type of experiment. Only one bag remained in situ. 
This single case was successful as far as it goes ; all the ovules, 
six in number, on the screened megasporophyll were found 
shrivelled two months later, although the sporophyll itself 
was still healthy. Further attempts are again being made on 
the same line, as well as experiments on artificial pollination. 
But we shall have to wait some time before finding out the 
effect of these tactics. 
On the other hand, the examination of full-grown ovules 
of G. Rum^Tiii, obtained from Peradeniya, has yielded con- 
clusive results. Pollen grains belonging either to Encepha- 
lartos or Macrozamia were found in the pollen chamber of 
these ovules ; they had germinated within the pollen chamber 
and penetrated the nucellus, and had no doubt given the 
necessary stimulus for the full growth of the ovule, although 
in no case had fertilization in the strict sense taken place. 
We have here then a case of foreign polHnation culminating 
in the production of a male gametophyte, which by penetrating 
the nucellus has given an impetus to the growth of the ovule, 
but which, because foreign, belonging to a different genus, was 
incapable of fertilizing the ovum and of producing an embryo ; 
that is to say, of producing a seed in the strict meaning of 
the word. This statement will receive justification from the 
description and explanation of the figures on Plate XIII. 
Fig. 1 shows a sketch of a megasporophyll of C. Bumphii 
considerably reduced in size. The sporophyll itself is about 
30 cm. long, and is narrower than that of G. circinalis. The 
serrate indentations represent pinnæ, and suggest a reduced 
foliage leaf ; the tip is entire, subulate, and some 6 cm. in 
length. The two healthy ovules (ov. ) are about two months old ; 
