162 THE AUSTRALIAN NATURALIST. 
plants from the attacks of insects and assist in the work of 
pollination. Mr. Hamilton exhibited an exhaustive series of 
slides to illustrate his remarks. In moving a vote of thanks 
to the lecturer Mr. Froggatt related several incidents deseriptiv2 
of the habits of the birds at the Sheep-fly experiment station 
‘at Moree. The motion was seconded by Miss Busby, who made 
some observations on the birds in her own aviary. The vote 
of thanks was carried by acclamation. 
MACROZAMIA OR BURRAWANG. 
By Agnes A. BREWSTER. 
This plant is a cycad belonging to the Family Cycadaceae, 
which are naked-seeded plants or Gymnosperms. Macrozama 
has an enlarged root-stock, and roots which bear bacterial no- 
dules. ‘The leaves are tough and pinnate. ‘The male and female 
cones are borne on separate plants. 
The Macrozamia plant is the sporophyte or asexual generation. 
It produces the cones or sporophores (spore carriers). 
The female cone (Fig 1) consists of a central rachis which 
is strong and woody. On this are found a number of stout, 
spined carpels or sporophylls (leaves carrying spores), which 
are arranged spirally. Hach carpel bears two ovules or macro- 
sporangia (Fig. 2). If a longitudinal section of this ovule is cut 
the following structures will be seen (Fig. 3); (a) the walls of 
the ovule called the integument, which protects the inner parts. 
At the apex of the integument is a narrow passage, the (b) 
micropyle, and the position of this can be identified by a tiny 
projection on the apex of the ovule. It allows the entrance of 
the pollen grains. Within the integument is a zone of tissue of 
many cells which is called the (c) nucellus (Fig. 3): this acts as 
a food store, and also protects the innermost part (ad) the emoryo 
sac or macrospore, which contains (e) the prothallium or game- 
tophyte: it is multicellular, consisting of numerous deiicate cells 
in which archegonia or female gametes are embedded at the 
apex: the neck cells of the archegonium of mosses is reduced 
here to a couple of cells. Note that whereas in Mosses the whole 
moss-plant body is the gametophyte, in Macrozama it is re- 
duced to this soft jelly-like tissue within the embryo-sae, and it 
never leaves the ovule or macrosporangium. The male cone has 
a central woody rachis on which are placed the microsporophylls 
