266 



4. Appearance of a 'viscid disc" on the rostellum. 



5. Development of a caudicle or its equivalent. 



6. Conversion of the pollinia from mealy or granular 

 into waxy masses. 



Both are in possession of some of the more recently 

 acquired characters of the Order, whereas in the one the 

 column has not yet developed, and in the other it is apparently 

 still in an early stage of evolution. 



II. On the Pollinary Mechanism of Phajus. 



Two species of Phajus indigenous to Queensland have 

 been accepted as valid by the late R. D. Fitzgerald, F. M. 

 Bailey, and other botanists. 



Fitzgerald, indeed, prepared a beautiful plate of each 

 of these, but did not live to complete the letter-press ; con- 

 sequently many important points connected with the pollinary 

 mechanism have been left in doubt. Recently the writer 

 has been fortunate enough to receive from Mr. C. T. White, 

 Director of the Brisbane Botanic Gardens, a quantity of 

 material which enables him to supply many details in regard 

 to these Australian species which have hitherto been obscure 

 or uncertain. 



In the case of P. grandif alius, Lour., the material avail- 

 able has been ample, and has represented satisfactorily the 

 various stages of development of the column in that species. 

 The earliest stages were scantily represented in P. Bernaysn y 

 Rowl., but the material is believed to have been sufficient on 

 which to base trustworthy conclusions. 



1. P. grandif olius, Lour. The structure of the column 

 at maturity is shown in Fitzgerald's illustration. The upper 

 part is dilated with fleshy wings. The anther is lid-like; it 

 is attached just above the clinandrium and is situated 

 horizontally over the stigmatic-cavity. The latter is, to a 

 very considerable extent, shut off by the upward growth of 

 its anterior margin, and by the inward encroachment of the 

 lateral ones which are produced into two triangular inturned 

 appendages. The appendages are continuous with the upper 

 border of the stigma which is immediately below the 

 clinandrium. There is no rostellum and no disc, so that the 

 clinandrium, which is exceedingly shallow and oblique, merges 

 almost insensibly into the stigma. 



The stigmatic-cavity is capacious and its lower part is in 

 free communication with the stigmatic-canal. Its surface 

 begins to function very early and secretes copiously even 

 before dehiscence of the anther. 



