RIDDLES IN FLOWERS 209 



our lives. Perhaps we may have chanced to ob- 

 serve that the flowers are not all constructed 

 alike, but the chances are that we have seen them 

 all our lives without discovering this fact. If we 

 pluck a few from this dense cluster beside the 

 path, we observe that the throat of each is swollen 

 larger than the tube beneath, and is almost closed 

 by four tiny yellow anthers (Fig. i). The next 

 and the next clump may show us similar flow- 

 ers ; but after a little search we are sure of find- 

 ing a cluster in which a new form appears, as 

 shown in Fig. 2, in which the anthers at the open- 

 ing are missing, and their place supplied with a 

 little forked stigma! The tube below is larger 

 than the first flower for about two -thirds its 

 length, when it suddenly contracts, and if we cut 

 it open we find the four anthers secreted near the 

 wide base of the tube. What does it mean, this 

 riddle of the bluets.'^ For hundreds of years it 

 puzzled the early botanists, only finally to be 

 solved by Darwin. This is simply the little plan 

 which the Houstonia has perfected to insure its 

 cross -fertilization by an insect, to compel an in- 

 sect to carry its pollen from one flower and de- 

 posit it upon the stigma of another. Once realiz- 

 ing this as the secret, we can readily see how per- 

 fectly the intention is fulfilled. 



In order to make it clear I have drawn a pro- 

 gressive series of pictures which hardly require 



