blossom Hosts and Insect Guests 



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 flowers ; 

 but after a little search we are sure of finding" a 

 cluster in which a new form appears, as shown in 

 Fig. 2, in which the anthers at the opening are miss- 

 ing, 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 sud- 

 denly 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 ? This 

 is simply the little plan which the Houstonia has per- 

 fected to insure its cross-fertilization by an insect, 

 to compel an insect to carry its pollen from one 

 flower and deposit it upon the stigma of another. 

 Once realizing this as the secret, we can readily see 

 how perfectly the intention is fulfilled. 



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

 gressive series of pictures, which hardly require 

 description. The flowers are not highly developed 

 enough to have a special insect sponsor. They are 

 visited by various small bees, butterflies and other 

 insects. At the left is an insect just alighting 



62 



