YUCCA MOTH AND YUCCA POLLINATION. 109 
brought within the range of a good lens, when all her move- 
ments may be observed to the greatest advantage without 
disturbing her. In this way I have been able to watch the 
consignment of hundreds of eggs, and to admire the delicacy 
and elasticity of the oviduct proper, which issues from the 
chitinous sheath in a silk-like thread, almost invisible to 
the naked eye. While being withdrawn it is seen to be as 
long as, or longer than, the terminal abdominal joint and 
stretches or bends as the body is raised or lowered, in 
freeing it from the pistil. Indeed this freeing is a laborious 
job, and occupies from forty seconds to two minutes. 
Oviposition rarely begins before dusk, and takes place 
only in the flowers which are newly opened, ¢. €., during the 
first or second nights after opening, as it is chiefly during 
these nights that the ovary is susceptible to pollination, the 
stigmatic tube and the ovules, which are at first open for 
the reception of the pollen, thereafter closing. The moth 
seems instinctively aware of this and is never found ovi- 
positing in the older flowers. Indeed, her actions indicate 
that she investigates closely not only the condition of the 
pistil as to development, but as to whether or not it has 
already been punctured. 
It may be well here, in order to more fully understand 
the action and influence of the moth, to look a little more 
closely into the characteristics of the Yucca flower at this 
stage of its development. A longitudinal section of the 
upper portion of the pistil will show us the style with its 
stigmatic tube, which, at this time, communicates with the 
ovarian cells. release (who will, I hope, accompany this 
article with some botanical details showing the pollen tubes 
and other microscopic structures) has shown that the stig- 
matic liquor is not nectarian, but that the slight amount 
of nectar which is associated with the flowers, is secreted in 
thin pockets formed by partitions that separate the three 
cells of the pistil and which open externally bya contracted 
pore from which the nectar is poured through a capillary 
tube (enclosed by the closely applied but not outwardly 
