Two things I have been anxious to bring out prominently in the foregoing chapters: that parental behaviour among the insects, reptiles and fishes presents us with a bewildering diversity of aspects—in particular, that the instinct of caring for the young is not fixed in the mother, but may be transferred from her to the father; and further, that all parental sacrifice, though often unconsciously expended to maintain the well-being of the family, is of direct benefit to the parent who bestows it, and is the surest means of developing and brightening such a parent’s individual intelligence. Now, I wish to elaborate and establish these two propositions with further examples in order that they may be laid hold of and firmly grasped as indubitable facts; and then we may come to see and understand the significance to ourselves of these unusually devoted fathers, which are found, and that not infrequently, among all classes of pre-human parents. The varied behaviour of bird-parents—more especially of the males—furnishes just the kind of evidence we need. There are several cases known, and I believe there must be others as yet unrecorded, wherein the conduct and, indeed, the whole character of the two sexes is reversed. Here the females, driven it would seem by a fierce sex-hunger, do the courting and fight one another as rivals for the males, while the males undertake all the family duties of incubation and brooding and the feeding of the young. The phalaropes, both the grey and the red-necked species, which are found in Scotland and Ireland, afford a striking example of these unsexed females. Among these birds the rôle of the sexes is reversed. The duties of incubation and rearing the young are conducted entirely by the male, and in correlation with this habit, the female does all the courting. She is stronger and more pugnacious than the male, and is also brighter in plumage. This is really very remarkable. What has acted in bringing about this reversal in the secondary sexual characters? Can the male nature be transferred to the female? These are difficult questions. In colour the phalaropes are a pale olive very thickly spotted and streaked with black. The male is the psychical mother, the female takes no notice of the nest after laying the eggs. Frequently at the beginning of the breeding season she is accompanied by more than one male, so that it is evident polyandry is practised.[30]