112 BULLETIN OF THE LABORATORIES 



lent classification for phanerogamic flowers, according to the complete- 

 ness with which they exclude self-fertilization. According to his' class- 

 ification the plant we have under consideration would come under 

 class B. Male and female organs in one and the same flower (mono- 

 clinism), division i. The organs of the two sexes not developed si- 

 multaneously (dichogamy), and subdivision (a.) The male before the 

 female. And the division might have been carried farther, as there 

 are several minor principles applied in different ways to the plants un- 

 der the last division. 



One of the most wonderful of the many contrivances for cross- 

 fertilization is found in the lobelia family. The calyx is adherent to 

 the two-celled ovary. The corolla is two-lipped ; the lower lip is three- 

 lobed; the upper lip is split and the division continued to the base of 

 the corolla. Through this slit the united filaments and anthers bend 

 out then in again over the lower lip. The anthers unite and form a 

 conical-shaped figure. The upper portion projects beyond the lower 

 (as in the case of a bird's beak) and forms the apex of the cone. A 

 spur extends downward from this upper portion, forming a hollowed 

 space. A clump of stiff hairs extends from the lower lip, and presses 

 closely up to the tip of the apex, closing the hollowed space, except a 

 small opening between the hairs and the spur in the back end. Now 

 the pistil is sheathed by the stamens. It has a broad two-lobed stig- 

 ma. Each lobe is protected by a sheath thickly covered with a ring 

 of stiff hairs. At first the pistil is considerably below the lower ex- 

 tremity of the anthers. The pistil keeps growing up through the tube 

 of the filaments, until it enters the chamber of the anthers at the 

 proper time for fertilization. The inner walls of the pollen cells have 

 by this time been absorbed, and the pollen has been let loose in the 

 chamber. The pistil steadily presses the pollen toward the vertex. 

 Escape backward is prevented by the broad stigma-lobes with their 

 ring of hairs, thus some of the pollen is pressed into the little space 

 at the vertex. When a bee alights on the lower lip and crawls down 

 the tube, the slit in the back of which allows it to be expanded, the 

 back of the bee bends down the stiff hairs. The i)ollen is hurled out 

 upon it because of the tension. The pollen is carried to another flow- 

 er and deposited on the stigma in the manner immediately to be ex- 

 plained. The pistil pushes on, driving out the pollen, and grows 

 through the aperture in the vertex, protruding over the lower lip. 

 Heretofore fertilization has been prevented by the sheaths. These are 



