FLORAL MECHANISMS 87 



"flags," rich purple in colour, and marked with dark 

 veins. These latter attract the attention of the 

 bumblebees, and form a welcome landing-stage for 

 them. But where are the very important pistils 

 and stamens? We have seen, without recognizing, 

 the former in the three-branched structure first 

 described, which consists in reality of three styles; 

 and the stigmas are the little tongues at their outer 

 ends, but the stigmatic surface of each, sensitive 

 and receptive, is on the upper and outer side 

 only. 



Now, to find the stamens, we must lift up or cut 

 away one of these arching styles. Hidden close 

 under it we will discover the anther laden with 

 pollen. 



The bumblebee, a frequent visitor to the iris, 

 seems to know exactly what is expected of him, for, 

 alighting on the drooping petal, and following the 

 guide-lines of its veins, he crawls crouching under 

 the arched pistil and down the low-vaulted pas- 

 sageway it forms, till he is able to reach down into 

 the nectary with his proboscis and drink his fill. 

 But, to leave these close quarters, he must back 

 out, and in so doing must necessarily brush his hairy 

 shoulders against the anther, dusting himself with 

 pollen. Backing still farther, he passes under the 

 little tongue, which, lifting, closes against the ears 



