Fig. 9. 
10. 
I1. 
12. 
Fig. 1. 
Fecundation in Orchidee and Asclepiadee. 735 
A pollen mass after bursting, with its cord formed of 
the pollen tubes, entering the apex of the style, which 
is there lacerated. 
The two Ovaria with their styles, one being somewhat 
enlarged in consequence of impregnation, and opened 
longitudinally ; exhibiting pollen tubes extending from 
the apex of the style to the commencement of the pla- 
centa. 
The same two ovaria and styles, both opened, to show 
that in one (the left), which is somewhat smaller, 
no pollen tubes are contained; the other (the right), 
which is impregnated, shows the tubes reaching the 
ovula, but not extending further. 
Two grains of pollen (or rather grains deprived of their 
outer membranes,) with portions of their tubes and 
contained spheroidal granules; proving that the tubes 
are extensions of this (the inner) membrane :—very 
highly magnified. 
Tas. 35. ASCLEPIAS PHYTOLACCOIDES. 
An expanded flower (magnified), from which two of the 
foliola coronz and one anthera have been removed. 
. The complete Pistillum, and on one side two of the 
antherz, the membrane formed by the united fila- 
ments being cut off a little below the stigma ; on the 
other side, a naked pollen mass applied to the stigma, 
with its gland and arm adhering. 
. A longitudinal section of fig. 2, to show on the left side 
a pollen mass, with a small portion only of the arm 
adhering, applied to the base of the stigma, and which, 
having burst, shows the protrusion of the cord formed 
by the pollen tubes. 
VOL. XVI. 5B Fig. 4. 
