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cylinder, are closely wrapped around the upper part of the style, 
which is shaped like a hairy, cylindrical brush. The anthers 
burst along their inner face at this time, and the brush, by means 
of the bristling hairs, sweeps the pollen out of them pretty 
cleanly. As they shrivel up and shrink away towards the-bottom 
of the bell-shaped corolla, the style lengthens, bearing the spheri- 
cal pollen grains with it while the flower is unfolding. The 
stigmas are still inaccesssible to the pollen, since they form the 
inner faces of the three-cleft style, the parts of which are closed 
on one another, and form the cylindrical brush. They soon open 
and curve backward, exposing their inner surfaces, now turned © 
outward and covered with stigmatic papillae. As they curve 
back, they hold the same position in the flowers as did the brush 
a little earlier. Hence an insect, creeping into the corolla to 
reach the nectar, rubs offsome pollen from the brush of a younger 
flower and carries it to the stigma of an older one, the parts of 
the style being curved back in such a way. that it cannot, if of 
any considerable size, avoid brushing off some of the dust and 
leaving it on the papillose stigmas. In this way, as an insect 
goes from flower to flower, the ovules of an earlier flower are 
fertilized by the pollen of a later one. 
The older botanists were puzzled to account for the fertilization 
of these plants. The relative position of the parts was well known 
to Linnzeus and his pupils! In a dissertation by one of them, 
Wahlbom, entitled, ‘“‘Sponsalia plantarum,” and read at Upsal 
in 1746, it is stated that certain canals existed in the style to 
carry the pollen through to the stigmas.* Sprengel remarks that 
they did not see these canals, but imagined them. It was an 
effort to bridge a difficulty, and, like many another, broke down 
when the test was made. . 
The function of the hairs fringing the bases of the stamens is 
considered by Miiller to be that of keeping useless visitors from 
the nectar stored in the fleshy disks just within. Strong insects 
like bees, that are the most common visitors of Campanule, can 
push through them and secure the nectar, the nectar-disks being 
covered by them and the “valves.” Weak insects will be kept 
away. Sprengel looked upon them as contrivances to protect the 
* Linnzus, Fundamenta Botanica, 1786, Vol. I, p. 246, 
