Neo-Darwinians further assert that the scents of flowers have been developed by natural selection because they serve to attract insect visitors to the flowers. In support of this contention it is urged that the most highly scented flowers are not usually the most conspicuous ones, since it is not necessary for a flower to be both highly coloured and strongly scented. Again, those flowers which open at night are usually very highly scented.
Plausible though this view seems, there are weighty objections to it. These are so admirably summarised by Kay Robinson in the issue of _The Country-Side_ for March 27, 1909, that we feel we cannot do better than reproduce his words:—
“It is true that many flowers which are strongly scented are visited by insects, but these flowers have abundance of nectar, and the insects come in spite of the scent, and not on account of it. They visit unscented flowers, provided that they have nectar, equally freely; and they do not visit flowers which have scent without nectar.
“Moreover, fruits are more generally scented even than flowers; but what explanation have those, who attribute the scents of flowers to the tastes of insects, for the scents of fruits? Insects which visit fruits are only robbers. Therefore, if we say that plants have scents for the purpose of attracting insects, we accuse all plants which have scented fruits of attempted suicide.
“There are hosts of plants, again, with scented leaves. Here also the insects are only robbers, and it is quite clear that the scent is not useful in attracting insects. If, therefore, you adopt the insect theory to explain the scents of flowers, you must invent entirely new theories to explain the scents of fruits and leaves.”
It is thus evident that the ordinarily accepted explanation of the colours, scents, and markings of flowers is far from satisfactory.
Mr E. Kay Robinson has put forth in recent issues of _The Country-Side_ (March 20, 27, and April 3, 1909) quite a new explanation of the phenomena, and one which deserves careful consideration. He maintains that “the real, primary, and original meaning of the colours, markings, nectar and scents of flowers is not to attract insects, but to deter grazing and browsing animals.”