Certainly it could not, but neither could other adaptations. Natural selection, as Darwin knew well enough, does not “produce” anything—all it can do is to depress the less favourable variations presented to it in favour of the more favourable ones. As Darwin never professed to have sounded the depths of the problem of variation, it is not clear why variations favourable to another species than the one in which they occur should be presumed to be impossible. It is true that they would not illustrate or come under the operation of natural selection, but neither would they contradict it—they would simply be outside it. Individuals unquestionably exhibit modifications intended not for their own personal benefit, but for that of the species—for instance, the maternal instincts. The modification of a part in the interest of the whole to which it belongs may, perhaps, turn out to have the same essential significance whether the part is an organ or instinct belonging to the synthesis called an individual, or an individual belonging to the synthesis called a species, or a species belonging to some fauna or flora of the globe. In any case, the question where synthesis is arrested, and where the fight for one’s own hand begins, is one of great interest and must be here briefly discussed. Cases such as those of which Darwin rejected the possibility certainly appear to be rare, if they exist at all. The naturalists of the older school, of course, saw them everywhere—the rattlesnake’s rattle was to warn its victims, the colouring of flowers was to give pleasure to man, and so forth. Most of these cases have been exploded by modern research. The modern naturalists, however, may not be right in refusing to see them anywhere. The question demands much special study and observation. Reverting to the case of flowers and their secretion of honey, one is struck by the fact that in the _Viola_ family there exist flowers more or less conspicuous, and endowed with scent and with honey-filled nectaries, which usually do not play any part at all in fertilization. The process of fertilization in _Viola_ is carried on by small flowers hidden under the leaves which never open, and which fertilize themselves. Again, at the base of the laurel leaf, on each side of the midrib, there are two small glands filled with honey, and bees may be observed biting into these in the early part of the year before flower-honey is plentiful. Nägeli has an ingenious argument to show the existence, not exactly of disinterested aid among species, but of something which would make such aid look more possible than it does, of a mutual responsiveness, namely, between the form of the honey-receptacles of certain flowers and the probosces of the insects which frequent them. Taking a short honey-tube as the normal and original condition among plants, and a short proboscis among insects, he argues that the honey-tube could not have lengthened without depriving the species in which it did so