32 THE FERTILISATION OF FLOWERS. [parr r. 
Coleoptera. 
In contrast to the foregoing groups, Coleoptera affurd un- 
equivocal adaptations to a floral diet. They are of far greater 
importance as fertilisers, for many species in widely different 
families feed at times on flowers, and a still greater number 
confine themselves to such food exclusively. None of our 
native plants are fertilised exclusively or even mainly by 
Coleoptera; but the large genus Meligethes alone, the species of 
which are small and can creep into most flowers, is of more 
importance as a fertilising agent than all the preceding groups 
taken together. On the other hand, beetles do great harm to 
many flowers by nibbling their reproductive organs. 
In flowers where te honey lies fully exposed (Ui mbelliferce; 
Cornus, Parnassia), many species of beetles may be seen licking 
it; and in flowers with exserted stamens and with the honey 
concealed though accessible to short-lipped insects (Rosiflore, 
Composite), beetles may be seen licking up honey, devouring 
pollen or even the whole anther, or nibbling at the petals and 
stamens. In flowers which have conspicuous anthers but which 
secrete no honey, or where the honey lies too deeply hidden, 
(Ranunculacee, Plantago), the beetles feed upon the pollen, the 
anthers, and other soft parts of the flower. Besides these, flowers 
which afford shelter from wind and rain (Campanula, Digitalis) 
are visited by beetles, which then feed upon the pollen and the soft 
tissues. In warmer countries, according to Delpino (178, L., p. 234), 
several flowers of this kind, eg. Magnolia, have become adapted 
for fertilisation by beetles (Cetonia) exclusively. Lastly, we 
sometimes find beetles upon flowers which seem to offer none 
of the advantages above described, but only allure by means of 
their bright colours; thus, for instance, Cryptocephalus sericeus 
and OC. Mori are often attracted by the bright yellow flowers of — 
Genista tinctoria. 
A review of the mode of life of insects sihdan visit flowers, 
and of the families to which they belong, shows continuous 
gradations from those which never visit flowers to those which 
seek them as a secondary matter, and finally to those which 
entirely depend upon them. This shows clearly that insects 
which originally did not avail themselves of flowers gradually 
became more and more habituated to a floral diet, and only 
