380 THE BIOLOGY OF FLOWERING PLANTS 



the pollen is often removed and deposited in a very definite 

 way. In floM^ers of class A, which are open, and visited by a 

 variety of small and large insects, the transference is carried out 

 simply by the " guests " scrambling at random over stigmas 

 and stamens. It is in the higher, and particularly in the 

 zygomorphic flowers, that more exact mechanisms are found. 

 We may take as an example the meadow sage, Salvia pratensis, 

 as described by Miiller (Fig. 54). The tube of the corolla is 

 horizontal and contains at its base a drop of nectar secreted 

 by axial glands. The corolla runs out in front into the broad 



Fig. 54. — Pollination of sage {Salvia pratensis) ; i, diagram of flower 

 with the corolla hood supposed transparent, to show position of stamens : 

 dotted lines show position of stamens when depressed and of style in 

 older flower ; 2, the stamens : A, lower, and B, upper half of connective, 

 C, lower halves of anthers forming the plate. Magnified. (After 

 MuUer.) 



lower lip, which forms the landing-stage for visiting bees, 

 and the arched and hooded upper lip, under which lie the 

 stamens and young style. There are only two functional 

 stamens, the anthers of which are borne on short, stout fila- 

 ments. The lower half of each anther is sterile, and, with its 

 neighbour, forms a broad plate which blocks the entrance 

 to the tube ; from it the connective, enormously elongated, 

 arches up under the upper lip of the corolla, and carries at 

 its tip the fertile half of the anther. The connective is not 

 rigidly fixed to the filament, but is pivoted, so that, if 



