20 PRESIDENTS ADDftESS. 



the visitor, which, in this case, is always an insect — mostly a fly 

 or a bee. At the same time, the style takes up a new position. 

 In Grevillete, Embothriea?, and Banksia?, the flowers are mostly 

 irregular and generally bird-pollinated, Lortiatia being an excep- 

 tion in the second of those tribes. (Lomatia, by the way, makes 

 a poor recompense to insect- workers. Some years ago, 1 recorded 

 the fact that flies feeding on the nectar died in numbers, and 

 Dr. Petrie thought that hydrocyanic acid was the cause. Re- 

 cently a correspondent has drawn Mr. Maidens attention to a 

 similar case. It is only at certain stages of flowerings that the 

 insects are killed). Among these, there is considerable diversity, 

 although the general plan is the same in all — the pollen is de- 

 posited in the bud-stage on the disc surrounding the stigma. 

 Then the style pulls itself free, and stands up. Birds visiting 

 the flowers remove the pollen and transfer it to the minute 

 stigmas of other flowers. Mr. Fletcher has drawn attention to 

 a very interesting case of crossing between GreviUea lavrifolin 

 and G. acanthi/olia; but he has not yet completed his observa- 

 tioDS. Hybrids among the Proteacei^ are only possible when both 

 parents have flower-heads of such a kind that the pollinatoi's 

 approach them in the same way, and styles of such a length that 

 the style-summit of each touches the bird in the same place. 

 Thus a species with a secund raceme would not be likely to be 

 pollinated from a species with a round head of flowers. The 

 only observations on Australian Proteacete by local botanists 

 that I have been able to trace are by Dr. Shirley(18), and a note 

 on Telopea and Stenocarpus by myself (19). Mr. W. M. Carne 

 favoured me with some MS. notes on GreviUea robusta, of which 

 the following is a precis. The flowers grow in a long, horizontal 

 raceme, and the basal ones open flrst. At the tip will be found( 1 ) 

 unopened flowers, or partly open, but with the stigma still 

 attached to the perianth. Proceeding towards the base of the 

 raceme, we find (2) the style free, with the pollen attached all 

 round the small, central stigma, which is not yet mature. Then 

 follow (3) flowers with the perianth bent away from the style, 

 pollen becoming dry, and a drop of nectar appearing in the 

 an^^le between the perianth and the stipes of the ovary. The 



