Professor Ainslie Grey had not come down to breakfast at the usual hour. The presentation chiming-clock which stood between the terra-cotta busts of Claude Bernard and of John Hunter upon the dining-room mantelpiece had rung out the half-hour and the three-quarters. Now its golden hand was verging upon the nine, and yet there were no signs of the master of the house.

It was an unprecedented occurrence. During the twelve years that she had kept house for him, his youngest sister had never known him a second behind his time. She sat now in front of the high silver coffee-pot, uncertain whether to order the gong to be resounded or to wait on in silence. Either course might be a mistake. Her brother was not a man who permitted mistakes.

Miss Ainslie Grey was rather above the middle height, thin, with peering, puckered eyes, and the rounded shoulders which mark the bookish woman. Her face was long and spare, flecked with colour above the cheek-bones, with a reasonable, thoughtful forehead, and a dash of absolute obstinacy in her thin lips and prominent chin. Snow white cuffs and collar, with a plain dark dress, cut with almost Quaker-like simplicity, bespoke the primness of her taste. An ebony cross hung over her flattened chest. She sat very upright in her chair, listening with raised eyebrows, and swinging her eye-glasses backwards and forwards with a nervous gesture which was peculiar to her.

Suddenly she gave a sharp, satisfied jerk of the head, and began to pour out the coffee. From outside there came the dull thudding sound of heavy feet upon thick carpet. The door swung open, and the Professor entered with a quick, nervous step. He nodded to his sister, and seating himself at the other side of the table, began to open the small pile of letters which lay beside his plate.

Professor Ainslie Grey was at that time forty-three years of age—nearly twelve years older than his sister. His career had been a brilliant one. At Edinburgh, at Cambridge, and at Vienna he had laid the foundations of his great reputation, both in physiology and in zoology.

His pamphlet, On the Mesoblastic Origin of Excitomotor Nerve Roots, had won him his fellowship of the Royal Society; and his researches, Upon the Nature of Bathybius, with some Remarks upon Lithococci, had been translated into at least three European languages. He had been referred to by one of the greatest living authorities as being the very type and embodiment of all that was best in modern science. No wonder, then, that when the commercial city of Birchespool decided to create a medical school, they were only too glad to confer the chair of physiology upon Mr. Ainslie Grey. They valued him the more from the conviction that their class was only one step in his upward journey, and that the first vacancy would remove him to some more illustrious seat of learning.

In person he was not unlike his sister. The same eyes, the same contour, the same intellectual forehead. His lips, however, were firmer, and his long, thin, lower jaw was sharper and more decided. He ran his finger and thumb down it from time to time, as he glanced over his letters.

“Those maids are very noisy,” he remarked, as a clack of tongues sounded in the distance.

“It is Sarah,” said his sister; “I shall speak about it.”

She had handed over his coffee-cup, and was sipping at her own, glancing furtively through her narrowed lids at the austere face of her brother.

“The first great advance of the human race,” said the Professor, “was when, by the development of their left frontal convolutions, they attained the power of speech. Their second advance was when they learned to control that power. Woman has not yet attained the second stage.”

He half closed his eyes as he spoke, and thrust his chin forward, but as he ceased he had a trick of suddenly opening both eyes very wide and staring sternly at his interlocutor.

“I am not garrulous, John,” said his sister.

“No, Ada; in many respects you approach the superior or male type.”

The Professor bowed over his egg with the manner of one who utters a courtly compliment; but the lady pouted, and gave an impatient little shrug of her shoulders.

“You were late this morning, John,” she remarked, after a pause.

“Yes, Ada; I slept badly. Some little cerebral congestion, no doubt due to over-stimulation of the centers of thought. I have been a little disturbed in my mind.”

His sister stared across at him in astonishment. The Professor’s mental processes had hitherto been as regular as his habits. Twelve years’ continual intercourse had taught her that he lived in a serene and rarefied atmosphere of scientific calm, high above the petty emotions which affect humbler minds.

“You are surprised, Ada,” he remarked. “Well, I cannot wonder at it. I should have been surprised myself if I had been told that I was so sensitive to vascular influences. For, after all, all disturbances are vascular if you probe them deep enough. I am thinking of getting married.”

“Not Mrs. O’James” cried Ada Grey, laying down her egg-spoon.

“My dear, you have the feminine quality of receptivity very remarkably developed. Mrs. O’James is the lady in question.”

“But you know so little of her. The Esdailes themselves know so little. She is really only an acquaintance, although she is staying at The Lindens. Would it not be wise to speak to Mrs. Esdaile first, John?”

“I do not think, Ada, that Mrs. Esdaile is at all likely to say anything which would materially affect my course of action. I have given the matter due consideration. The scientific mind is slow at arriving at conclusions, but having once formed them, it is not prone to change. Matrimony is the natural condition of the human race. I have, as you know, been so engaged in academical and other work, that I have had no time to devote to merely personal questions. It is different now, and I see no valid reason why I should forego this opportunity of seeking a suitable helpmate.”

“And you are engaged?”

“Hardly that, Ada. I ventured yesterday to indicate to the lady that I was prepared to submit to the common lot of humanity. I shall wait upon her after my morning lecture, and learn how far my proposals meet with her acquiescence. But you frown, Ada!”

His sister started, and made an effort to conceal her expression of annoyance. She even stammered out some few words of congratulation, but a vacant look had come into her brother’s eyes, and he was evidently not listening to her.

“I am sure, John, that I wish you the happiness which you deserve. If I hesitated at all, it is because I know how much is at stake, and because the thing is so sudden, so unexpected.” Her thin white hand stole up to the black cross upon her bosom. “These are moments when we need guidance, John. If I could persuade you to turn to spiritual——”

The Professor waved the suggestion away with a deprecating hand.

“It is useless to reopen that question,” he said. “We cannot argue upon it. You assume more than I can grant. I am forced to dispute your premises. We have no common basis.”

His sister sighed.

“You have no faith,” she said.

“I have faith in those great evolutionary forces which are leading the human race to some unknown but elevated goal.”

“You believe in nothing.”

“On the contrary, my dear Ada, I believe in the differentiation of protoplasm.”

She shook her head sadly. It was the one subject upon which she ventured to dispute her brother’s infallibility.

“This is rather beside the question,” remarked the Professor, folding up his napkin. “If I am not mistaken, there is some possibility of another matrimonial event occurring in the family. Eh, Ada? What!”

His small eyes glittered with sly facetiousness as he shot a twinkle at his sister. She sat very stiff, and traced patterns upon the cloth with the sugar-tongs.

“Dr. James M’Murdo O’Brien——” said the Professor, sonorously.

“Don’t, John, don’t!” cried Miss Ainslie Grey.

“Dr. James M’Murdo O’Brien,” continued her brother inexorably, “is a man who has already made his mark upon the science of the day. He is my first and my most distinguished pupil. I assure you, Ada, that his ‘Remarks upon the Bile-Pigments, with special reference to Urobilin,’ is likely to live as a classic. It is not too much to say that he has revolutionised our views about urobilin.”

He paused, but his sister sat silent, with bent head and flushed cheeks. The little ebony cross rose and fell with her hurried breathings.

“Dr. James M’Murdo O’Brien has, as you know, the offer of the physiological chair at Melbourne. He has been in Australia five years, and has a brilliant future before him. To-day he leaves us for Edinburgh, and in two months’ time, he goes out to take over his new duties. You know his feeling towards you. It, rests with you as to whether he goes out alone. Speaking for myself, I cannot imagine any higher mission for a woman of culture than to go through life in the company of a man who is capable of such a research as that which Dr. James M’Murdo O’Brien has brought to a successful conclusion.”

“He has not spoken to me,” murmured the lady.

“Ah, there are signs which are more subtle than speech,” said her brother, wagging his head. “But you are pale. Your vasomotor system is excited. Your arterioles have contracted. Let me entreat you to compose yourself. I think I hear the carriage. I fancy that you may have a visitor this morning, Ada. You will excuse me now.”

With a quick glance at the clock he strode off into the hall, and within a few minutes he was rattling in his quiet, well-appointed brougham through the brick-lined streets of Birchespool.

His lecture over, Professor Ainslie Grey paid a visit to his laboratory, where he adjusted several scientific instruments, made a note as to the progress of three separate infusions of bacteria, cut half-a-dozen sections with a microtome, and finally resolved the difficulties of seven different gentlemen, who were pursuing researches in as many separate lines of inquiry. Having thus conscientiously and methodically completed the routine of his duties, he returned to his carriage and ordered the coachman to drive him to The Lindens. His face as he drove was cold and impassive, but he drew his fingers from time to time down his prominent chin with a jerky, twitchy movement.

The Lindens was an old-fashioned, ivy-clad house which had once been in the country, but was now caught in the long, red-brick feelers of the growing city. It still stood back from the road in the privacy of its own grounds. A winding path, lined with laurel bushes, led to the arched and porticoed entrance. To the right was a lawn, and at the far side, under the shadow of a hawthorn, a lady sat in a garden-chair with a book in her hands. At the click of the gate she started, and the Professor, catching sight of her, turned away from the door, and strode in her direction.

“What! won’t you go in and see Mrs. Esdaile?” she asked, sweeping out from under the shadow of the hawthorn.

She was a small woman, strongly feminine, from the rich coils of her light-coloured hair to the dainty garden slipper which peeped from under her cream-tinted dress. One tiny well-gloved hand was outstretched in greeting, while the other pressed a thick, green-covered volume against her side. Her decision and quick, tactful manner bespoke the mature woman of the world; but her upraised face had preserved a girlish and even infantile expression of innocence in its large, fearless, grey eyes, and sensitive, humorous mouth. Mrs. O’James was a widow, and she was two-and-thirty years of age; but neither fact could have been deduced from her appearance.

“You will surely go in and see Mrs. Esdaile,” she repeated, glancing up at him with eyes which had in them something between a challenge and a caress.

“I did not come to see Mrs. Esdaile,” he answered, with no relaxation of his cold and grave manner; “I came to see you.”

“I am sure I should be highly honoured,” she said, with just the slightest little touch of brogue in her accent. “What are the students to do without their Professor?”

“I have already completed my academic duties. Take my arm, and we shall walk in the sunshine. Surely we cannot wonder that Eastern people should have made a deity of the sun. It is the great beneficent force of Nature—man’s ally against cold, sterility, and all that is abhorrent to him. What were you reading?”

“Hale’s Matter and Life.”

The Professor raised his thick eyebrows.

“Hale!” he said, and then again in a kind of whisper, “Hale!”

“You differ from him?” she asked.

“It is not I who differ from him. I am only a monad—a thing of no moment. The whole tendency of the highest plane of modern thought differs from him. He defends the indefensible. He is an excellent observer, but a feeble reasoner. I should not recommend you to found your conclusions upon Hale.”

“I must read Nature’s Chronicle to counteract his pernicious influence,” said Mrs. O’James, with a soft, cooing laugh.

Nature’s Chronicle was one of the many books in which Professor Ainslie Grey had enforced the negative doctrines of scientific agnosticism.

“It is a faulty work,” said he; “I cannot recommend it. I would rather refer you to the standard writings of some of my older and more eloquent colleagues.”

There was a pause in their talk as they paced up and down on the green, velvet-like lawn in the genial sunshine.

“Have you thought at all,” he asked at last, “of the matter upon which I spoke to you last night?”

She said nothing, but walked by his side with her eyes averted and her face aslant.

“I would not hurry you unduly,” he continued. “I know that it is a matter which can scarcely be decided off-hand. In my own case, it cost me some thought before I ventured to make the suggestion. I am not an emotional man, but I am conscious in your presence of the great evolutionary instinct which makes either sex the complement of the other.”

“You believe in love, then?” she asked, with a twinkling, upward glance.

“I am forced to.”

“And yet you can deny the soul?”

“How far these questions are psychic and how far material is still sub judice,” said the Professor, with an air of toleration. “Protoplasm may prove to be the physical basis of love as well as of life.”

“How inflexible you are!” she exclaimed; “you would draw love down to the level of physics.”

“Or draw physics up to the level of love.”

“Come, that is much better,” she cried, with her sympathetic laugh. “That is really very pretty, and puts science in quite a delightful light.”

Her eyes sparkled, and she tossed her chin with the pretty, wilful air of a woman who is mistress of the situation.

“I have reason to believe,” said the Professor, “that my position here will prove to be only a stepping-stone to some wider scene of scientific activity. Yet, even here, my chair brings me in some fifteen hundred pounds a year, which is supplemented by a few hundreds from my books. I should therefore be in a position to provide you with those comforts to which you are accustomed. So much for my pecuniary position. As to my constitution, it has always been sound. I have never suffered from any illness in my life, save fleeting attacks of cephalalgia, the result of too prolonged a stimulation of the centres of cerebration. My father and mother had no sign of any morbid diathesis, but I will not conceal from you that my grandfather was afflicted with podagra.”

Mrs. O’James looked startled.

“Is that very serious?” she asked.

“It is gout,” said the Professor.

“Oh, is that all? It sounded much worse than that.”

“It is a grave taint, but I trust that I shall not be a victim to atavism. I have laid these facts before you because they are factors which cannot be overlooked in forming your decision. May I ask now whether you see your way to accepting my proposal?”

He paused in his walk, and looked earnestly and expectantly down at her.

A struggle was evidently going on in her mind. Her eyes were cast down, her little slipper tapped the lawn, and her fingers played nervously with her chatelain. Suddenly, with a sharp, quick gesture which had in it something of ABANDON and recklessness, she held out her hand to her companion.

“I accept,” she said.

They were standing under the shadow of the hawthorn. He stooped gravely down, and kissed her glove-covered fingers.

“I trust that you may never have cause to regret your decision,” he said.

“I trust that you never may,” she cried, with a heaving breast.

There were tears in her eyes, and her lips twitched with some strong emotion.

“Come into the sunshine again,” said he. “It is the great restorative. Your nerves are shaken. Some little congestion of the medulla and pons. It is always instructive to reduce psychic or emotional conditions to their physical equivalents. You feel that your anchor is still firm in a bottom of ascertained fact.”

“But it is so dreadfully unromantic,” said Mrs. O’James, with her old twinkle.

“Romance is the offspring of imagination and of ignorance. Where science throws her calm, clear light there is happily no room for romance.”

“But is not love romance?” she asked.

“Not at all. Love has been taken away from the poets, and has been brought within the domain of true science. It may prove to be one of the great cosmic elementary forces. When the atom of hydrogen draws the atom of chlorine towards it to form the perfected molecule of hydrochloric acid, the force which it exerts may be intrinsically similar to that which draws me to you. Attraction and repulsion appear to be the primary forces. This is attraction.”

“And here is repulsion,” said Mrs. O’James, as a stout, florid lady came sweeping across the lawn in their direction. “So glad you have come out, Mrs. Esdaile! Here is Professor Grey.”

“How do you do, Professor?” said the lady, with some little pomposity of manner. “You were very wise to stay out here on so lovely a day. Is it not heavenly?”

“It is certainly very fine weather,” the Professor answered.

“Listen to the wind sighing in the trees!” cried Mrs. Esdaile, holding up one finger. “It is Nature’s lullaby. Could you not imagine it, Professor Grey, to be the whisperings of angels?”

“The idea had not occurred to me, madam.”

“Ah, Professor, I have always the same complaint against you. A want of rapport with the deeper meanings of nature. Shall I say a want of imagination. You do not feel an emotional thrill at the singing of that thrush?”

“I confess that I am not conscious of one, Mrs. Esdaile.”

“Or at the delicate tint of that background of leaves? See the rich greens!”

“Chlorophyll,” murmured the Professor.

“Science is so hopelessly prosaic. It dissects and labels, and loses sight of the great things in its attention to the little ones. You have a poor opinion of woman’s intellect, Professor Grey. I think that I have heard you say so.”

“It is a question of avoirdupois,” said the Professor, closing his eyes and shrugging his shoulders. “The female cerebrum averages two ounces less in weight than the male. No doubt there are exceptions. Nature is always elastic.”

“But the heaviest thing is not always the strongest,” said Mrs. O’James, laughing. “Isn’t there a law of compensation in science? May we not hope to make up in quality for what we lack in quantity?”

“I think not,” remarked the Professor, gravely. “But there is your luncheon-gong. No, thank you, Mrs. Esdaile, I cannot stay. My carriage is waiting. Good-bye. Good-bye, Mrs. O’James.”

He raised his hat and stalked slowly away among the laurel bushes.

“He has no taste,” said Mrs. Esdaile—“no eye for beauty.”

“On the contrary,” Mrs. O’James answered, with a saucy little jerk of the chin. “He has just asked me to be his wife.”

As Professor Ainslie Grey ascended the st............