“Things are now spoilt, sometimes each of the four that are experimented on settles apart, sometimes the same burrow contains the two males or the two females, sometimes the same crypt the two sexes, but differently associated from what they were at first. I have abused my powers of repetition. Henceforth disorder reigns. My daily shufflings have demoralised the burrowers, a crumbling home always requiring to be begun afresh has put an end to lawful associations. Respectable married life becomes impossible from the moment when the house falls in from day to day.” I have now said enough, I think, to show that at many different levels in the insect kingdom the parental instinct is already developed. Pre-eminent in virtue is the behaviour of the dung-beetle parents. And this is all the more interesting as it proves how closely related good parenthood is with the conditions of the home and the form of marriage. A few more words may here be added to what has been said already concerning the influence of intelligence on instinct. It is a difficult question, but, speaking roughly, intelligence may be said to act in two opposite ways; that is, it may aid both in the making and the unmaking of instincts.[15] Thus the dung-beetles frequently change their conduct, and they do this by modifying their instincts through intelligent adaptation. It is scarcely too much to say that with them intelligence reaches its highest form of originality. Why is this? Fabre gives us the answer. “The more the maternal instinct asserts itself, the higher does instinct ascend.” It would be better probably if the word instinct were used in a more restricted sense: it should not be regarded as being able to explain everything. This mysterious impulse is held to direct all pre-human parents in their conduct to their young. Very well; but what of the directing force behind? The evidence is strong that even the lowliest creatures have their own problems, and are able to solve them. Can we explain otherwise the wide difference in conduct between parent and parent? Do we know what it is that gives a special direction to the instinctive activities in the accomplishment of a design greater than any of these parents know? We cannot answer fully. But instinct has its twin brother in intelligence, and, acting together, they are the guardians of life. When real things are so wonderful, what can we do but note them and try to understand? Not elsewhere in the insect world do we meet with a devotion more complete than that of both the dung-parents; not elsewhere do we find a finer development of intelligence. These two things are related and closely dependent, the one upon the other. It is this fact that now I am seeking to establish. Sacrifice in the parent does not lead to limitation, but to expansion.