FLOWERS OF THE PROTEACE. 571 
the plants in attracting suitable insect guests, and in preventing 
others from visiting undesirable spots, or in guiding insects along 
. such tracks only as will best serve to promote fertilisation. 
The reason why one species requires an annular nectary shutting 
the sexual organs off from insects crawling from below, while others 
possess an opening through the nectary, deserves further study. 
The genera of this order divide naturally into two sections ; in 
the first section are included all those plants in which the style is 
much longer than the perianth, and is consequently much pro- 
truded ; to this section belong Banksia, Hakea, Grevillea, and others; 
in the second section the style is not muchlonger than the perianth, 
and almost wholly covered by it when the perianth has expanded, 
as in Persoonia, Conospermum, and Synaphea. 
As an example of the long-styled orders, Grevillea may be 
taken. The flowers of the beef-woods are usually long, narrow, 
and irregular. The style usually protrudes by its middle from a 
slit in the perianth, its end being held fast, in the middle of the 
anthers, by the still coherent tips of the perianth lobes; but at 
this stage the stigma is immature. When the style-end is freed 
it rises covered with viscid masses of pollen. These masses 
gradually dry and fall away, or are brushed from the style-end by 
visitors—either birds or insects. If examined at this stage the 
style is found to be without a canal for pollen tubes, and there is 
no stigmatic tissue at its tip. An examination of transverse 
sections of the base of the style shows that the cavity of the style 
first develops there, and that its inner surface is clothed with cells 
resembling those of stigmatic tissue. This tube is gradually 
developed from the base upwards, and when it reaches the style- 
end, then, and then only, is a true stigma formed, and the flower 
becomes capable of fertilisation. 
Although the structure of the style of Proteaceous plants has 
much in common with that of normal forms, the tip, before the 
growth of the style canal is completed, is lined within with peculiar, 
large, thick-walled, dotted cells, probably a nutritive tissue absorbed 
by the lining tissue of the style-tube, and whose functions are 
worth further investigation. 
In a spike of Grevillea flowers the lowest have styles with a 
true stigmatic surface. The central ones have immature styles 
coated with pollen. The apical ones are still hooked in the 
perianths, and, where the style-end is adherent to the petals, are 
clothed round the line of attachment with a copious supply of 
honey. Parrots and honey-eaters frequent the plants at this and 
earlier stages, clinging below the flowers, and reaching to the apex 
of the inflorescence where most honey lies. In doing so they 
brush the pollen from the central flowers on their feathers, and, 
visiting the next branch, attach the grains to the lower stigmas of 
the next inflorescence, thus fertilising them. 
