Marvels of the Universe 1151 
She then crawls a little way up the leaf, and from the other side of 
the midrib makes another curving cut to the opposite edge. In one 
of the accompanying photographs this stage of the work has just 
been reached, and the weevil is seen taking her customary spell of 
rest. Probably she remains inactive because, by waiting, the lower 
part of the leaf wilts somewhat, and thus becomes more manage- 
~ able. Yet the success of her subsequent operation depends mainly 
> upon the accuracy of the cuts which she has made in the leaf. 
These cuts have been examined by mathematicians, who have pro- 
nounced the curves to be exactly those which are necessary to render 
the rolling of the leaf most easy for the insect to accomplish. 
Nevertheless, there is reason for thinking that the weevil’s instinct is 
not infallible, for one may often see half-rolled leaves which have 
Photo by] Poin man, seem abandoned, apparently because the insect’s strength proved 
Wels SSNs inadequate for the completion of the work. Probably in such cases, 
A magnified view of the Weevil at ; 
ian aera en en er LIC Lomein alyculavedacutsywere at fault. 
shown in the other photos. When the leaf has become sufficiently pliable, the weevil goes 
round to the back—7.e., the under-surface of the leaf 
and, beginning at the point where she first 
cut the tissue, gradually rolls one side of the leaf inwards to the midrib. This part of the work 
can quite easily be watched by an observer who has the necessary patience at command. Sub- 
sequently, however, the weevil changes her tactics, and draws the second half of the leaf round 
that which has already been rolled, incidentally wrapping herself over, so that we can only judge 
from the slow tightening of the folds that the work is still progressing. It is at this stage—z-e., 
when the weevil is hidden from view—that the eggs are laid. Thereafter, the insect creeps out, 
tightens up the roll, and fastens down the overlap with her snout. 
The appearance of the leaf below the cuts is now very much like the “screw” of paper which 
a grocer makes to hold a 
pound of moist sugar ; and 
the insect completes the 
resemblance by making the 
tip of the leaf into a smaller 
funnel, which is eventually 
tucked in with due care. 
Then comes a curious little 
ritual, the significance of 
which is not quite clear. 
The weevil climbs up the 
leaf, and deliberately 
wounds the midrib at the 
point where her first curved 
cut meets it. It has been 
suggested that she does 
this in order to promote 
the particular state of de- 
cay which will render the 
leaf suitable as food for 
her grubs. Be this as it Photo by] 
may, the fact remains that 
(A. H. Bastin. 
FINISHED WORK OF THE LEAF-ROLLER. 
The three examples here shown should be considered from right to left. They show 
she often completely severs the final stages of tightening up, and tucking up the previously open lower end. 
