Lydgate talked persistently when they were in his work-room, putting arguments for and against the probability of certain biological views; but he had none of those definite things to say or to show which give the waymarks of a patient uninterrupted pursuit, such as he used himself to insist on, saying that "there must be a systole and diastole in all inquiry," and that "a man's mind must be continually expanding and shrinking between the whole human horizon and the horizon of an object-glass.

POLARITY, or action and reaction, we meet in every part of nature; in darkness and light; in heat and cold; in the ebb and flow of waters; in male and female; in the inspiration and expiration of plants and animals; in the equation of quantity and quality in the fluids of the animal body; in the systole and diastole of the heart; in the undulations of fluids, and of sound; in the centrifugal and centripetal gravity; in electricity, galvanism, and chemical affinity.