139 
and much elongated ducts, while in others* their secreting surface 
is increased by a more or less sinuous development, resulting in 
prominent longitudinal folds in the last two genera referred to, 
and other epigynous Bromeliacee, where the three glands are 
also, for a part of their extent, confluent, merging into the intra- 
carpellary cavity, although they do not appear to discharge 
through this at the stigma, their ducts offering a freer exit for 
the nectar into the base of the flower. 
The glands of Yucca play a very unimportant part in the 
pollination of the flowers, a fact which apparently explains the 
partial loss of secreting power, and is unquestionably connected 
with their adaptation to the good services ofthe Yucca-moth. In 
watching a good many of these insects at night, while engaged 
in pollinating the flowers and depositing their eggs, I saw only a 
single one attempt to feed, and this tried to probe the three 
_ glands of a flower at the point D, where the glands open into the 
conducting grooves. Whether it succeeded in penetrating into 
the latter or not could not be seen. It remained at each gland 
not over two or three seconds, and on leaving the flower was 
captured and proved to bea male. During the day the moths 
of both sexes, as well as the bogus Yucca-moth ( Prodoxus), re- 
main in the flowers, commonly standing on the filaments with 
their heads at the bottom of the corolla. My impression is that 
they feed at this time; but the disturbance necessitated by open- 
ing the partly closed flowers is sufficient to cause them to stop, if 
this is true, and I have, in point of fact, never seen them thus 
engaged. 
I was not able to see the insects Ete in collecting pollen, — o 
but there isno reason to doubt the entire accuracy of Professor 
Riley’s statement} that the females deliberately go to the stamens 
and accumulate a supply of pollen on their remarkable spinose ten- 
tacles, before beginning the work of pollination and oviposition. 
While engaged in this work, as he has stated, they will bear the full 
blaze of a lantern in the flower, and may even be watched through a 
lens without desisting, though, if the light is too suddenly turned» 
* Strelitzia, \. c., pl. 4, f.6; Melinonia,\. c., sale 3, f. 1-4; Billbergia, 1. Ce f i 
6-10. t 
t Amer. Naturalist, avi, pabag pp. 62, 2, 63.4 GFtO) 
ses Cisse, ey Ahir, Pex GFR) ex, ts 
