Chap. IV. SPIKANTHES AUTUMN ALIS. 113 



younger flowers. Nevertlieless, a flower which in its 

 early state had not been visited by insects would not 

 necessarily, in its later and more expanded condition, 

 have its pollen wasted : for insects, in inserting and 

 withdrawing their proboscides, bow them forwards or 

 upwards, and would thus often strike the furrow in the 

 rostellum. I imitated this action with a bristle, and 

 often succeeded in withdrawing the pollinia from old 

 flowers. I was led to make this trial from having at 

 first chosen old flowers for examination ; and on passing 

 a bristle, or fine culm of grass, straight down into 

 the nectary, the pollinia were never withdrawn ; but 

 when it was bowed forward, I succeeded. Flowers 

 which have not had their pollinia removed can be 

 fertilised as easily as those which have lost them ; and 

 I have seen not a few cases of flowers with their 

 pollinia still in place, with sheets of pollen on their 

 stigmas. 



At Torquay I watched for about half an hour a 

 number of these flowers growing together, and saw 

 three humble-bees of two kinds visit them. I caught 

 one and examined its proboscis : on the superior 

 lamina, some little way from the tip, two perfect 

 pollinia were attached, and three other boat-formed 

 discs without pollen ; so that this bee had removed 

 the pollinia from five flowers, and had probably left 

 the pollen of three on the stigmas of other flowers. 

 The next day I watched the same flowers for a quarter 

 of an hour, and caught another humble-bee at work ; 

 one perfect poliinium and four boat-formed discs ad- 

 hered to its proboscis, one on the top of the other, 

 showing how exactly the same part of the rostellum 

 had each time been touched. 



The bees always alighted at the bottom of the 

 spike, and, crawling spirally up it, sucked one flower 



