YUCCA MOTH AND YUCCA POLLINATION, 107 
and reaching to the opposite side of the stamen. In 
this manner she is able to obtain a firm hold of the stamen 
while the head is kept close to the anther and moved pe- 
culiarly back and forth, something as in the motion of the. 
head of a caterpillar when feeding. (PI. 38, Fig. 2.). The 
maxillary palpi are used in this act very much as the or- 
dinary mandibles are used in other insects, removing or 
scraping the pollen from the anthers toward the tentacles. 
After thus gathering the pollen, she raises her head and com- 
mences to shape it into a little mass or pellet by using her 
front legs very much as a cat does when cleansing her 
mouth, sometimes using only one leg, at another time both, 
smoothing and pressing the gathered pollen, the tentacles 
meanwhile stretching and curving. After collecting all 
the pollen from one anther, she proceeds to another and 
repeats the operation, then to a third and fourth, after 
which, with her relatively large load — often thrice as large 
as the head — held firmly against the neck and front tro- 
chanters, she usually runs about or flies to another plant ; 
for I have often noticed that oviposition, as a rule, is ac- 
complished in some other flower than that from which the 
pollen was gathered, and that cross-fertilization is thus 
secured. 
Once fully equipped with this important commodity, 
she may be seen either crawling over or resting within 
the flower, generally with the head toward the base. From 
time to time she makes a sudden dart and deftly runs 
around the stamens, and anon takes a position with the 
body between and the legs straddling two of them, her head 
being usually turned toward the stigma. As the terminal 
halves of the stamens are always more or less recurved, 
she generally has to retreat between two of them until the 
tip of her abdomen can reach the pistil. (PI. 37, Fig. 2). 
As soon as a favorable point is reached, generally just below 
the middle, she rests motionless for a short time, when the 
abdomen is slightly raised and the lance-like ovipositor 1s 
thrust into the soft tissue, held there the best part of a 
