2 5 ” Cross-Pertilia sation in Flowers. [January, 
sepal. Is it not well adapted for tripping the smaller insects, or 
raising them, so that they shall hit the stamen and stigma, forcing 
them by increased activity, or by their walking on its top, to com- 
pensate for lack of size? In this arrangement of parts in the 
Iris we have the main features of a plan which is traceable in 
many other flowers. 
Strangely enough uoy irregular oe eara seem to 
copy this regular p 
in its method of cross-fertiliza- 
tion. This is especially true of 
Martynia proboscidea Glox., the 
unicorn plant. The general form 
and structure of the flower is - 
shown in the figures. The 
lower petal forms a broad plat- 
form upon which the bee 
alights. As it enters the tube 
(which I believe is broader be- 
fore fertilization, the roof rising 
Fic.. 2.—Side view of Martynia ro- as the corolla fades), it first 
biecheteds: ` (Natural size.) A 
brushes the lower lip of the _ 
stigma, Fig. 3 a, then while getting the nectar at the bottom of ~ 
the tube its back is dusted by the anthers. As it withdraws, the — ; 
| 
: 
Ae 
N a ATTA tet rye 
= i 
uy thy 
Bee eee 
flexible lobe of the pistil, like a valve, allows the pollen to pass 
without touching the stigma, 
which is on its upper or inner 
surface. This lower lobe is 
very sensitive before fertiliza- 
tion, during which time it hangs 
nearly vertical. In the case ot} 
a flower kept for examination, 
as soon as it was touched with 
; a mass of pollen it rose toward 
E E e e ARE 
flexible lobe of stigma as its motion was very perceptible. 
In the Penstemons (my obser- 
vations are mainly upon one species, P. >, glaucus [?] Grah 3, we 
oe snag Se ane on. 
_ Central Nebraska. The species was not familiar to me: I made a hasty sketch a 
the flower as given. Certain notes of the characters of the plant were taken, but not 
- enough to decisively distinguish it from the many species of the same = IC 
gin n that — 
