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range of the centrally set stigma. In Gresneria, however, this 
difficulty is overcome. In the first place, the stigma is very 
broad, so as to cover a large range. Then the anthers are 
individually very narrow, and, moreover, adhere to each other 
by their edges, so that the four together form a disk no broader 
than the stigma, immediately in front of which it lies (figs. 9, a 9 
and 10). The dehiscence of these coherent anthers is, as usual, 
on the anterior face, that is, on the side turned away from the 
stio-ma. Thus, a bee entering the corolla soon after its ex- 
pansion will get a smudge of pollen on the median line of its 
back. It will not touch the stigma, for this is shielded by the 
anther-disk. But when the flower has been some time open, 
a change occurs in the position of the parts. The filaments 
bend forwards, and carry the disk away from the stigma right 
across the corolla, until it comes into contact with the anterior 
lip, where it remains fixed (fig. 9, b). It is plain that when a 
bee visits a flower in this later condition, the same spot on its 
back, which in the earlier stage came in contact with the 
anther-disk, will now come in contact with the stigma: for this 
occupies the same position as did the disk, and is, moreover, of 
the same breadth. Thus in Gresneria — as in so many other cases 
the more mature flowers are fertilised by the pollen of the 
less mature. 
Antirrhinum . — The general arrangement of style and sta- 
mens in snapdragon is the same as in foxglove ; but the per- 
sistent closure of the mouth of the corolla might seem a certain 
proof that the fertilisation is independent of insects. Any one, 
however, who watches the flowers with a little patience will 
soon see that the closure is not sufficient to exclude bees. 
Sometimes a bee will be seen trying in vain to force an en- 
trance ; but in such case the flower is, I believe, invariably 
immature. So soon as the anthers are open, the tightness of 
the closure relaxes sufficiently to allow the bees to force their 
way in without any great exertion, and I have repeatedly seen 
them do so. 
That such visits are required for due fertilisation I have, 
moreover, found on experiment. I covered a large Antirrhinum 
with a tent of gauze, so arranged as to exclude bees. The plant 
flowered abundantly ; but though in other Antirrhinums close 
by, which were not so protected, scarcely a single flower failed 
to be fertilised, only two small capsules were produced from all 
the numerous flowers of the protected plant ; and even of these 
two it was doubtful whether the fertilisation was not due to an 
accidental rent in the gauze that occurred towards the end of 
the experiment, and was not immediately mended ; so that 
possibly a bee may have got in at that period. 
I was much struck in this and a few similar experiments by 
