Trelease.] 
482 
[March 15 , 
to lie close to the sides of the corolla with their shrunken anthers 
at either side of the sac in its floor. Accompanying this motion 
is a slight curvature of the style which brings the stigma into the 
center of the plane previously occupied by the polliniferous part 
of the anthers, fig. 41. So far I have been unable to see that the 
appearance of the stigma changes with age. Its two lobes differ 
exteriorly in texture from the style, and have not been seen to 
expand at any time, so that the normal bilobed stigma of the 
family is here apparently reduced to a notched organ whose 
whole surface is stigmatic, fig. 44. Although the time when the 
stigma first becomes receptive has not been actually demonstrated, 
the flower is probably protandrous. Beneath the ovary is a large 
gland which secretes nectar, fig. 45. This fluid is protected from 
rain by the hairs on the fertile filaments and on the rudiments of 
the second pair, which, aiding in the formation of an efficient 
nectar guard, have been preserved. This nectar guard is evi- 
dently of further value in excluding insects too small to effect the 
transfer of pollen, though quite as eager for nectar as their larger 
congeners. In this office it is jaerhaps aided by the fine pubescence 
of the outside of the corolla, the scattered hairs about its mouth, 
and the spines and glandular hairs of the anthers and style ; 
the last two performing a duty similar to that of the hairs on the 
style of Salvia gesneriaefolia. 
The form and color of the flowers, their nectar and the succes- 
sive occupation of the same limited area of pollination by the 
anthers and stigma, clearly point to diurnal insects as the polli- 
nating agents ; and of these large bees like Bombus seem best 
fitted to transfer pollen while gathering nectar. The variegation 
of the corolla, and the colored anthers are points that insects soon 
connect with the location of the nectar, and may thus serve as 
nectar marks. A bee of the kind indicated can creep bodily into 
the inflated part of the corolla as far as the bend, its tongue read- 
ily reaching the nectar from this point. In doing this its back 
will brush the anthers or stigma, according as the flower is young 
or old. Beginning at the bottom of the inflorescence and work- 
ing upward, the bee effects crossing between distinct racemes 
or plants since the older pistillate flowers lie below those which 
are younger and staminate in function. 
