" cycle of nine days holds good then the professor at his worst to-night," said Holmes "The fact strange symptoms began after his visit to Prague, that in secret correspondence with Bohemian dealer in London, who presumably represents someone in Prague, he received packet this very day, all point in one direction What he takes and why he takes it are still beyond our ken, but emanates in some way from Prague is clear enough He takes it under definite directions which regulate this ninth-day system, the first point which attracted my attention But his symptoms are most remarkable Did you observe his knuckles ? "

I had to confess that

"Thick and horny in way quite new in my experience Always look hands first, Watson Then cuffs, trouserknees, and boots Very curious knuckles which can only be explained mode of progression observed by --" Holmes paused and suddenly clapped his hand forehead "Oh, Watson, Watson, what fool ! It seems incredible, and yet it true All points in one direction How could I miss seeing the connection of ideas ? Those knuckles how could passed those knuckles ? dog ! ivy ! It's surely time that I disappeared into that little farm dreams Look out, Watson ! Here ! the chance of seeing for ourselves "

The hall door had slowly opened, and against the lamplit background we saw the tall figure of Professor Presbury clad dressing gown As he stood outlined doorway erect but leaning forward with dangling arms, as when we saw him last

Now he stepped forward drive, and an extraordinary change came over him He sank down into crouching position and moved along upon his hands and feet, skipping every he were overflowing with energy and vitality He moved along the face house and then round the corner As he disappeared Bennett slipped hall door and softly followed him

"Come, Watson, come ! " cried Holmes, and we stole as softly as bushes until we had gained spot whence we the other side house, bathed light half-moon The professor was clearly visible crouching foot ivy-covered wall watched him he suddenly began with incredible agility to ascend it From branch to branch he sprang, sure of foot and firm of grasp, climbing apparently in mere joy at his own powers, with no definite object in view dressing-gown flapping on each side of him, he looked like some huge bat glued against the side own house, great square dark patch moonlit wall Presently he tired amusement, and, dropping from branch to branch, he squatted down old attitude and moved towards the stables, creeping along same strange way as before The wolfhound was out now, barking furiously, and more excited than ever when it actually caught sight master straining on its chain and quivering with eagerness and rage The professor squatted down very deliberately just out of reach hound and began to provoke it in every possible way handfuls of pebbles drive and threw them dog's face, prodded him with stick which he had picked up, flicked his hands about only few inches gaping mouth, and endeavoured in every way to increase the animal's fury, already beyond all control In all our adventures know that ever seen more strange sight than this impassive and still dignified figure crouching frog-like ground and goading to wilder exhibition of passion the maddened hound, which ramped and raged in front of him, by all manner of ingenious and calculated cruelty

And then in moment it happened ! not the chain that broke, but it collar that slipped, made for thick-necked Newfoundland We heard the rattle of falling metal, next instant dog and man were rolling ground together, the one roaring in rage, the other screaming in strange shrill falsetto of terror very narrow thing professor's life The savage creature had him fairly throat, its fangs had bitten deep, and senseless before reach them and drag the two apart It dangerous task , but Bennett's voice and presence brought the great wolflhound instantly to reason The uproar had brought the sleepy and astonished coachman room above the stables "I'm not surprised," said he, shaking his head "I've seen him at it before the dog would get him sooner or later "

The hound was secured, and together we carried the professor up room, where Bennett, who had medical degree, helped me to dress his torn throat The sharp teeth had passed dangerously near the carotid artery, haemorrhage was serious In half an hour the danger was past, I had given the patient an injection of morphia, and he had sunk into deep sleep Then, and only then, were we able to look at and stock situation

" first-class surgeon him," said I

"For God's sake, no ! " cried Bennett "At present the scandal is confined to our own household safe gets beyond these walls never stop Consider his position university, his European reputation, the feelings daughter "

"Quite so," said Holmes " it quite possible the matter to ourselves, and also its recurrence now that free hand The key watch-chain, Mr Bennett Macphail will guard the patient any change what find professor's mysterious box "

not much, but enough -- an empty phial, another nearly full, hypodermic syringe, several letters in crabbed, foreign hand The marks envelopes showed were those which had disturbed the routine secretary, and each was dated Commercial Road and signed "A Dorak " They were mere invoices that fresh bottle was being sent to Professor Presbury, or receipt to acknowledge money one other envelope, however, in more educated hand and bearing the Austrian stamp postmark of Prague "Here our material ! " cried Holmes as he tore out the enclosure

HONOURED COLLEAGUE [it ran]: Since your esteemed visit thought much of your case, and though in your circumstances some special reasons treatment, none the less enjoin caution, as my results have shown not without danger of kind possible serum of anthropoid better , as I explained , used black-faced langur because specimen was accessible Langur is, , crawler and climber, while anthropoid walks erect in all ways nearer I beg you every possible precaution that there be no premature revelation process one other client in England, and Dorak is my agent for both

Weekly reports will oblige Yours with high esteem, H LOWENSTEIN

Lowenstein ! The name brought back the memory of some snippet from newspaper which spoke of an obscure scientist who was striving in some unknown way secret of rejuvenescence elixir of life Lowenstein of Prague ! Lowenstein wondrous strength-giving serum, tabooed profession because he refused to reveal its source In few words what I remembered Bennett had taken manual of zoology shelves " 'Langur ' " he read " 'the great black-faced monkey Himalayan slopes, biggest and most human of climbing monkeys Many details are added Well, thanks , Mr Holmes, very clear that traced the evil to its source "

"The real source," said Holmes, "lies, , untimely love affair which gave our impetuous professor the idea that only gain his wish by turning himself into younger man When one tries to rise above Nature one is liable below it The highest type of man may revert animal if he leaves the straight road of destiny " He sat musing for little phial hand, looking clear liquid within "When written man and told him that I hold him criminally responsible poisons which he circulates, no more trouble But it may recur Others may find better way danger there -- very real danger to humanity Consider, Watson, material, the sensual, the worldly would all prolong their worthless lives The spiritual avoid the call to something higher It the survival least fit What sort of cesspool may not our poor world become ? " Suddenly the dreamer disappeared, and Holmes, the man of action, sprang chair " nothing more said, Mr Bennett The various incidents will now fit themselves easily general scheme The dog, , was aware change far more quickly than you His smell would insure that It monkey, not the professor, whom Roy attacked, just as it monkey who teased Roy Climbing was joy creature, and mere chance, I take it, pastime brought him young lady's window an early train to town, Watson, but just have time for cup of tea Chequers before we catch it "