| PART 111. | THE MECHANISMS OF FLOWERS. - 139 
bees and by Lepidoptera, one drone-fly, Rhingia, coming also to 
share the honey. The benefit which results from and has brought 
about the lengthening of the tube in Lychnis flos-cuculi lies in the 
fact that, by excluding short-lipped insects from the honey, a larger 
_ number of insects with long proboscides are tempted to come, and 
these, requiring more food, are more diligent in their visits and in 
their work as cross-fertilisers. That the exserted anthers can be , 
robbed by pollen-eating flies and pollen-collecting bees is scarcely 
 adisadvantage; for the pollen is seldom completely removed, and 
_ these pollen-seeking insects act as subordinate fertilisers. 
When the passage to the honey is still further lengthened and 
__harrowed, as in the species of Dianthus, Saponaria, and Lychnis, 
even bees are excluded and Lepidoptera only can gain access. For 
this result to be advantageous we must suppose that the visits of 
Lepidoptera are the better insured by exclusion of other insects. 
Exposure of the anthers is as little injurious here as in Lychnis 
_ flos-cuculi. As the honey gets more deeply concealed, and access 
more strictly limited to butterflies, we find pari passu among the 
| Caryophyllee increasing development of sweet scents, bright red 
colours, fine markings round the entrance of the flower, and 
{ indentations at the circumference. All these characters, which are 
so attractive to us, seem to have been produced by the similar 
tastes of butterflies. 
Orv. HYPERICACEZ. 
68. HypERICUM PERFORATUM, L.—The flowers, from their size 
and bright colour, and from numerous plants being usually 
associated together, are very conspicuous, and attract many insects 
seeking both honey and pollen; they however contain no honey, 
' and possess no contrivances to insure cross-fertilisation. The 
large production of pollen, and the capability for self-fertilisa- 
‘a en compensate in part for these disadvantages. ‘The numerous 
amens, usually over eighty in number, radiate from the bottom 
a of the flower in three groups, which are united at the base; the 
anthers are directed upwards and dehisce in rather. aaaine 
centrifugal succession, covering themselves with pollen. The 
three styles also radiate outwards, so that their terminal stigmas, 
which are developed simultaneously with the anthers, come 
to stand on a level with the anthers in the intervals between 
the groups of stamens. Since these. staminal bundles usually 
touch one another, and sometimes interlock slightly at their 
Re 
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