THE FERTILIZATIOX OF ORCHIDS. Jt 



labellum, or lip, are two guiding plates set up on edge, which 

 form a sort of passage leading direct to the mouth of the 

 nectary. Bear in mind that the pollen-clubs, though they 

 cannot be shaken out of the anther or knocked out, can very 

 easily be drawn out from the bottom, like sticks out of a 

 bundle, and that the little box held fast by its lid opens 

 downwards at the least pressure on the front, and you will 

 see a most admirable trap ready laid, and wanting nothing 

 but somebody or something to spring it. 



A moth approaches, flying busily about in search of nectar, 

 for bees are by no means the only insects who search for it, 

 in fact, bees seldom visit orchids. He perches on the label- 

 lum, and led by the guiding plates, puts his proboscis straight 

 into the nectary ; it is longer than he thinks for, and the 

 nectar must be reached by pushing the proboscis further and 

 further in. At last the proboscis presses the outside of the 

 little box, and the box, yielding to the push, opens. Now 

 the proboscis touches the little sticky disc at the bottom of the 

 pollen clubs as the unthinking insect sucks in his delicious 

 draught, and when, having drained the cup of joy to its very 

 dregs, he withdraws his trunk, he draws out with it the sticky 

 disc, and two clubs of pollen, which stand up like little horns 

 on either side of his nose. — So ends the first act. The 

 cement at once sets hard, but that is not all, the pollen-clubs 

 thus set upright would be of no use to fertilise the n^t 

 flower the insect might visit. As he pushed in to the nectary 

 they would but assume a position as close as possible to that 

 from which they had been taken, and no good would be 

 done. Now listen and wonder. As soon as the cement has 

 set, one side of the club-stalks contracts and draws the clubs 

 outward like a capital V. Barely is this motion completed 

 than another side contracts and draws the clubs forward like 

 the same capital V laid flat. Now the insect comes to a fresh 

 flower, pushes into it, the tips of his clubs in their new posi- 

 tion strike upon the stigmatic surface, and the stickiness of 

 this surface, forced into full play by the pushing of the insect, 

 takes hold of the pollen-masses and pulls off" some of the 

 pollen-dust, held closely together by its network of threads, 

 not strong enough to resist altogether the influence of the stick- 

 iness of the stigmatic surface, but too strong to let go all their 

 precious dust at once. Thus then the moth goes from flower 



