PART LIT. | THE MECHANISMS OF FLOWERS. 83 
14, DELPHINIUM ELATUM, L.—This common garden plant is 
marked off by the unusual function of the two whorls of the 
perianth from most other plants, and in part even from other 
species of larkspur; while it agrees with the latter in the early 
development of the stamens and in the peculiar movements of 
_ the stamens and stigmas. 
Fig. 28.—Delphinium elatum, L. 
1.— Young flower after removal of the calyx, seen from before. . 
2.—The petals in their natural position, seen obliquely from before and below. 
3.—Young flower after removal of the right half of the calyx. 
4.—Older flower after removal of the calyx, seen from before. 
5.—The sume flower as 3, after the right half of the corolla also has been removed. 
aa, the two upper petals, which are prolonged backwards into two spurs, which secrete and 
contain honey, and which in front form an entrance for the bee’s proboscis ; a*, their bases ; b b, 
_ the two inferior petals, whose closely approximated surfaces bound the entrance for the bee’s 
proboscis below—on their upper surfaces, each has a tuft of yellow hairs to serve as a path-finder, 
_ while their peduncles (b’,2 stand so far apart that in the first stage the anthers, in the second the 
stigmas, appear between them (at b*, 2) in the path of the insect’s re c, anthers whichhave 
_dehisced, placed in the way of the insect’s proboscis ; d, anthers which have not yet dehisced, bent 
downwards, covering the female organs; e, base of the stamens and carpels, which have been 
removed ; f, withered stamens bent downwards ; g, ovaries ; h, stigmas which have ss themselves 
in the same spot that the dehiscent anthers occupied in the first stage; i, left half of the upper 
_ sepal. prolonged backwards into a long sheath for the spur (#’); i, left lateral sepal; 1, left inferior 
a 
3 and 5, natural size; 1, 2, and 4, enlarged, 
The five large, blue, expanded sepals make the flowers visible 
_ from far off to humble-bees, and serve the purpose of a corolla. 
_ The hollow spur of the uppermost sepal neither secretes nor 
contains honey. Its peculiar rough and crumpled wall serves 
| rather as a cover for the organs which secrete and conceal the 
honey, which without it would be exposed to the rain; and also 
G 2 
