136 
to the behavior of the Yucca moth (TZegeticula Yuccasella, Riley), 
while in the flowers, but mainly to the necessity for its interven- 
tion in their fructification. 
Since reading his articles, I have hada suspicion that Professor 
Riley must have been mistaken in his belief that the stigmatic 
cavity is nectariferous,* as I know of no instance in which a 
liliaceous flower possesses a stigmatic nectary. But it was not 
until the present spring that I had an opportunity to give the 
flowers a careful examination. I then found, as I had expected; 
that the stigmatic tube contains no secretion aside from that 
which is customary to organs of this character, namely the slight 
amount of moisture, of a more or less gummy nature, that 
apparently serves as a stimulus to the nascent pollen-tubes. 
- iss 
A 
In Yucca, as in many other Liliacez and related endogens, 
the nectar glands (G, figs. 1 and 2) occur within the partitions 
that separate the three cells of the pistil, forming thin pockets 
extending nearly from the base to the summit of the ovary. 
These pockets are entirely closed except’ at the top, where they 
open externally by a contracted pore (D, fig. 1). Nevertheless, 
they represent superficial structures, since they occur within the 
suture corresponding to the external (dorsal) surfaces of the 
* Trans, St. Louis Acad,, iii., 59,60, 
3 
