134 MALAXE.3E. Chap. V. 



had it not been for the membranous expansions on 

 each side of the column forming the clinandrum, 

 within which they lie safely. 



When an insect inserts its proboscis or head into 

 the narrow space between the upright labellum and 

 the rostellum, it will infallibly touch the little pro- 

 jecting viscid mass, and as soon as it flies away it 

 will withdraw the pollinia. I easily imitated this 

 action by inserting any small object into the tubular 

 flower between the labellnm and rostellum. When 

 the insect visits another flower, the very thin pollen- 

 leaves attached parallel to the proboscis, or head, will 

 be forced into the pocket-like stigma with their broad 

 ends foremost. I found pollinia in this position glued 

 to the upper membranous expansion of the rostellum, 

 and with a large number of pollen-tubes penetrating 

 the stigmatic tissue. The use of the thin layer of 

 viscid matter, which coats the surface of the rostellum 

 in this genus and in Microstylis, and which is of no 

 use for the transportal of the pollen from flower to 

 flower, seems to be to keep the leaves of pollen fixed 

 in the narrow stigmatic cavity when their lower ends 

 have been inserted by insects. This fact is rather 

 interesting under a homological point of view, for, as 

 we shall hereafter see, the primordial nature of the 

 viscid matter of the rostellum is that which is common 

 to the stigmatic secretion of most flowers, namely, the 

 retention of the pollen, when placed by any means on 

 its stigma. 



The flowers of the Malaxis, though so small and 

 inconspicuous, are highly attractive to insects. This 

 was shown by the pollinia having been removed from 

 all the flowers on the spikes which I examined, 

 excepting from one or two close under the buds. In 

 some old flower-spikes every single poUinium had 



