"You can go now, Beau. We are finishing work for today. Put the chains on their pussies again and let them here for the night."

She watched as the mulatto girl obeyed her.

"Good girls," she said as she caressed one of the fillies. "You have given your cream for the first time; there will be others, because this thing is very important to us humans. Tomorrow we will put reins on you and teach you to walk with a person on you. Aren't you happy?"

"Yes, mistress," said one of the fillies. Linda looked at her badge: she was Ginga, a filly from Kumbo, as the earring indicated. Her mother was Tonga, to whom she resembled very much. Linda touched the belt lock over her pants and sighed. Still some days to go...

"Mistress, are we going to pull carts too?" Ginga's girlish voice asked. She had come near Linda and the chain from her pussy was fully stretched. She groaned as she felt the tug, and went a step back.

"Yes, certainly, this is what black centauresses do, and also other things, as you have seen," said Linda.

"But why have we to stay with this thing on us?"

"Because Master said so," was the reply. "You belong to him, never forget that."

She slapped gently Ginga's rump and watched as the girl shivered. Then she locked the stall and took a long glance at Beau's slender body, as she walked gracefully away towards her room. Linda would give a month's salary to go after her and have her lick her soles again; but that would have to wait. She was belted like a medieval woman; still surprised, she asked herself why she had agreed to such a thing. As she could not figure that out, she shook her head and went up to the lab, where she put the flasks in the fridge together with the one from Beau.

It was darkening; another day had passed in the Centaur Ranch. Dinner should be ready; Linda went to the house in a brisk pace, feeling the contact of the cold metal on her pussy and wondering how good it would be when Sean released her.

21. Linda restrained

The next morning, James and Linda sat by the computer as it processed the slides made from the cream samples they had collected from the centauresses and from Beau. A special program had been installed, and the screen showed a pattern of lines in a sort of graph. James superposed the images and said:

"You see, Linda, it is intriguing... Look here, the curves from the girl match for some inches those from the females. This means that some parts of the DNA chain are the same."

"James, I am still puzzled how it is easy to control these beasts. With simple commands, we are able to make them perform almost duty. And now Beau started to call us whites "master.".. Any idea of why?"

"I think that these centaurs have sprung from some still unknown mutation. You know that there was runaway Negro slaves in this area. They may have got some mares to relieve themselves. Usually this would give nothing, but it seems that here we had a most unlikely result: the DNA's mingled and the offspring was fertile. I am not sure, but this is at least a working hypothesis."

Linda was standing; she put her head to the microscope and took some notes. James could not help feeling his cock bulge as he watched the gracious curve of her ass; Sean had told him about the belt, and he was eager to see it. The girl felt his gaze on her and turned her head; her face was red with shame.

"Linda? Are you well?"

"Yes, why?"

"May I ask what is this under your pants?"

Linda gasped. "It is... er... ah... Sean suggested an experiment..."

James feigned not to be aware.

"An experiment?"

"Yes... he said that we are to study female sexual responses..."

"I see... and...?"

"And..." She took a deep breath. "And I am wearing a ...a ..."

"A what, Linda?" James was savoring her embarrassment.

"A chastity belt," she said and buried her face in her hands.

"Oh, but this is quite natural... I understand that you have to be restrained, so that you don't yield to any temptations, and then be examined, is that correct?" Linda nodded.

"Linda, would you allow me to see it?"

The girl's eyes opened wide, showing her astonishment at that request. James waited calmly as she made up her mind.

"Well... I don't think it would do any harm," she said. James smiled as she lowered her pants. The belt was shining on her pussy, a lock well visible on the triangular buckle. James sniffed between her legs:

"You are in some heat, aren't you, Linda?"

"Oh, James, this is unbearable... You don't know how it feels here!"

"I can imagine, but it is probably necessary," said the scientist. "And how do you use the toilet?"

Linda turned her back to him. He saw the opening for the asshole and instantly decided that he had to fuck that inviting, rosy circle. Too bad if she could not arrive to climax; he would not rape her, of course, but he wanted that and would not accept any negatives.

"Linda, you know what... I will ask Sean to give you some relief, but you have to do me a favor..."

"What is it?" she asked.

"I want to try you here," said James, rubbing the girl's ass hole with his finger.

"Oh!" Her face went blank with surprise. "Do you mean that I have to ... with the belt on... how could I? I do not come with ... er... with penetration here..."

"Well, it is up to you. If you agree, I might persuade Sean to let you have some pleasure soon. If not, you will have to wait."

Linda thought quickly. The tension in her clit was becoming unbearable. She did not particularly like ass fucking, but it seemed the only way to get out of that horrible thing, even for some minutes. She sighed; there was no alternative. Moving slowly to the desk, she held it with her hands, parted her legs and put up her ass cheeks.

James took his cock out and rubbed it on the small rosy hole. He put some saliva to his finger and wetted the girl; then he slowly slid his cock inside her and felt the firm pressure on his tip. Inch by inch, he moved into her, and, when he was halfway in, he commanded:

"You move back and forth, dear... Do your work..."

Linda was humiliated, but she complied. She could feel the cock entering her, throbbing from pleasure against the tight walls of her ass. James licked her neck and put his hands to her breasts; her nipples were rock hard, her whole body shaking with unfulfilled desire. The scientist lowered his hand and played with the lock of the belt, thrusting faster against the firm, white cheeks. Linda was breathing heavily, her labia itching with the need to be relieved.

"Milk me with your muscles, dear! Yes, like this... you do it so well!"

Linda did as she was told; then she felt the man spurting his juice inside her, kissing her back and licking her spine in quick, lascivious movements. He took his cock out and watched the girl gasping in desire, her slender body exposed to him.

"I will go for the key, Linda. But I want you to feel a special feeling... May I?" He opened a drawer and took out a chain about three feet long. He passed it swiftly inside the metal semicircle over the lock and hooked it to the desk bolt. Linda was so stunned that she could not think of a reaction.

"Now walk a bit," ordered James.

The girl walked as long as the chain would allow her. James smiled and told her:

"Now, you go back and hold the desk again. Stay so until I come back with the key. This way you will see how a centauress feels when she is attached by her pussy."

He left her there and went to meet Sean. They conferred quickly and James received the key to Linda's belt, as well as the measurer. He came back to the lab and took a long glance at the girl's body bent over the desk, her ass exposed, the chain dangling from her belt. He said:

"Linda, you are a true scientist! Now please stand up, I will release you. But first I have to cuff your hands behind you."

He went to her and cuffed her hands. Then he opened the belt and said:

"I know that you want most of all to touch yourself, but I have to measure you first." He rubbed her labia with the measurer and heard her moan in response. The scale showed maximum tension.

"Please, James, please... I can't stand this anymore... You will not lock this again, will you?"

"I have to," he replied. "Sean said you will be in for longer and longer periods, until you can stay locked a whole week without complaining."

Linda's eyes grew wide in terror.

"What?"

"Yes, dear. You have been locked for..." – he consulted his watch – "exactly 18 hours, and you are already in maximum tension. We will take note of that; next period will be, say, 30 or 36 hours, and we will increase the duration of the restraint. Now," he proceeded in spite of her terrified expression, "I suppose you need to have something done to this cunt..." He kneeled and took a long lick at the drenched labia, feeling the acre taste of her nectar.

"It is not like the centauresses," he said. "You probably do not have any Negro ancestry." Linda moved her body on the man's tongue, anxious to be relieved. But he took his face out and said:

"We will try another way. I will put this crop on the ground; you will kneel, insert it in you, and we will measure how long it takes for you to come."

"No! Please! Not that!" Linda's voice was anguished.

"If you prefer, I can lock you up again." James's voice was cold.

The girl looked at him in despair.

"I will do it... please... please... I need some relief!"

James placed the crop upright on the floor and helped the girl to squat on her heels. Linda felt the leathered hard handle slowly sliding into her pussy; she held it with her thighs and started to move up and down, her hands tied to her back, trying to discover how to take pleasure from that thing. She did not notice as Sean came silently into the lab and smiled: the girl was going up and down, her feet balls supporting her weight, her pussy clenching the handle of the crop in an effort to have her orgasm.

Sean moved to her and without a word took his cock out. Linda grabbed it with her mouth, moving up and down faster and faster. As she was approaching her climax, she began to shiver and sucked hard on Sean's cock; then she came, letting all the pent-up tension escape in a series of spasms.

"Five minutes and thirty five seconds," said James.

Linda looked at him; Sean's hand was gently grabbing her hair.

"You will make a foot job on me with those perfect feet, Linda," he said. "Beau did it the other day, and I want to compare the sensations."

Linda lay on her back and accommodated her cuffed hands under her body. She took Sean's cock between her feet and rubbed it; as she had very sensitive soles, she could feel every pulsation of the man's cock. Sean closed his eyes and let her work his cock; in less than two minutes, he exploded in a big orgasm, shooting sperm all over the girl's feet.

"Good! I have to say that you equal Beau in this," he said with a smile. "Now stand up, and back to the belt!"

"Sean, please... I want to stop ... I cannot go on... It is too hard!"

Sean looked at her.

"Do you prefer to be pierced and have a ring to control you?"

Linda's face went blank. Sean smiled:

"Of course I would not pierce you, Linda... It is a joke! Rings are for Beau and the centauresses, not for you. But please remember that we are doing an important experiment, and I request you to go on with it. I am appealing to your sense of responsibility... Please now stand up and open your legs. James?"

James took the belt and adjusted it to Linda's waist. He rubbed gently her clit with his finger, feeling the wetness; he measured her tension, which was low now, and slowly put the metal stem into the buckle. He then freed her hands, and said:

"You will close it yourself... please do it!"

The girl's hand trembled as she clasped the lock. "How long will I have to stay with this on?"

"Let us try a twenty-four hour length of time," said Sean. "Now you dress and put those fillies to work. I want them trained in carrying people, and then in going together in a cart. I have plans to tour the farm pulled by two young centauresses, and I trust you to prepare them."

Linda dressed herself and went to the fillies stall. She put reins and a saddle on Ginga and mounted her. She was somewhat angry, and kicked the girl's ribs with her heels.

"Out you go, Ginga! And follow my commands, ok?"

The centauress felt the weight of the girl on her back; she could sense that the human girl was tense, and the tugs on her collar were not very gentle. She understood quickly what she had to do, and left in a steady pace towards the fields. Linda swatted her rump with the crop and yelled:

"Galloping! Fast!"

Ginga had never been whipped before. She felt the sting of the crop and began to run, thinking that she would escape it. Linda whipped her again; the tension in her pussy was growing again, and she had to release it making the centauress feel that she was in command. Ginga saw a small pond and jumped perfectly over it; she was panting from the effort of running, but her jockey was not giving her any rest. Linda could feel the strong equine muscles moving under her; the girl's naked breasts moved up and down, her collar drenched with sweat, breathing heavily as she galloped around the farm fence. Linda pulled the reins and Ginga slowed down, then she stopped.

They were by the meadow. Linda pulled a small bowl from her pocket and said:

"You go there and bring me some water. Then you can drink."

She leaned against a tree and watched as the centauress filled her bowl with water and brought it obediently to her. She was very pretty; her slender body shone in the sun, her braids were a bit disheveled, and her face showed that she was tired. Although she had just reached adult age, this was the first time that she had been ridden in serious.

"You did well, Ginga," said Linda, as she felt less angry after the ride. She caressed the girl's chin. "You will be a fine mother too, when a male covers you. You want that, don't you?"

"Yes, Miss Linda."

"But I think Master will have you first. And you will like it, I am sure..."

As she said those words, she noticed a small speckle at a distance, coming towards them. It was Beau, riding a cart where the two other fillies had been harnessed. They were pulling with no apparent effort; as they approached, Linda saw their collars attached to each other, as it was becoming the custom with every centaur team. Beau led them to the meadow and took them out of their harness, but left them collared together.

"You go together and drink, then you come back here," she said.

Linda watched as they went cautiously to the meadow and lowered their heads at the same time to drink from it. She was pleased to see the first generation of foals born in the farm begin their training; she knew that in the foalry there were around thirty colts and fillies, growing up to a life of work either on that farm or where Sean chose to sell them to.

They went back together to the stalls, Linda mounting Ginga and Beau conducting the cart with Kenga and Nara, the other filly. Nara was also a daughter of Kumbo, but with Suli; she had the strength of her parents, and was a bit less elegant than Kenga. Beau kept swatting her gently with the crop, because she tended to stay behind her companion; she wanted them to walk together, so that the rider on the cart could be as comfortable as possible.

22. Training the new generation

They arrived to the stalls and let the mares eat and rest. Soon James and Sean appeared in the enclosure; they were eager to taste the new additions to the adult herd.

"I will take Kenga," said Sean. "I want to see if she is as good as her mother Dara. Which of the others do you prefer?"

James took a glance at the young mares. He lifted their tails and rubbed his finger over the slits; Ginga's labia seemed fuller, and her black torso was very nice seen from behind.

"This one," he said. Sean turned their rings on and waited. The mares began to thump ground with their legs, as the waves of heat crossed through their young, firm bodies. Sean went to Kenga and caressed her breasts, feeling the small nipples harden under his fingers. He snapped his fingers:

"Now, Kenga, put up your rump... Yes, like this... Today you will learn some very important things!"

He was pleased to see how easily the mare followed his command. He was still behind her; he slid a finger above her lips, feeling them moist and thick. He bent and had a long lick at them; he inserted his tongue in her, feeling the wet walls of her pussy, and let her milk his tongue with her movements. His cock went hard with the smell and taste of the still untouched cunt; Dara's daughter was now whining softly.

"You are delicious, Kenga... But you have to wait for your master, just as every mare in this farm has. Even the big males have to obey, you know that!"

She was playing with her nipples.

"Has your master told you to do that? Put your hands behind your back, Kenga."

She obeyed, sighing loud as the ring stimulated her more and more. Sean went round and sat in front of her.

"Now I want you to open your mouth and lick my cock, as a good black centauress has to," he said. She did as she was told; Sean could feel her hot, wet tongue sliding up and down his cock, as she breathed more and more quickly in her lust. He ran his fingers through her braids and felt the thick black hair on her head; when he felt almost on the verge of coming, he pushed her head and went quickly behind her.

"Stand up, but keep your hands on your back!" he ordered. Kenga obeyed her master. "Now spread your legs... like this... yes..."

He stood on a small stool to allow his cock to be at the right height, and entered her with a low movement, feeling the hard walls of her still virgin pussy. Sean remembered how he had deflowered her mother in the first day of their association. An association, he thought as he thrust faster his dick into the young mare's pussy that brought many advantages... at least to him. Kenga was feeling a cock's touch for the first time; her instincts told her to move back and forth, clenching her muscles on her master's rod.

Sean could see the ring sliding over his cock as she worked it; he let her do as she pleased, and watched as she moved faster and faster, her clit swollen as she rubbed it on the upper face of his member. Kenga felt suddenly an explosion inside her; she whined loud, stunned at the sensation. Sean decided to do as he remembered having done with Dara: he went out of her, made her bend her front legs and rubbed his cock on her cheek. In thirty seconds he had come, spurting his juice all over her black face.

"Clean it with your mouth!" he said curtly. "You are very gifted for this, Kenga, like your mother... Your future owner will be very pleased..."

As he felt her magical tongue sliding again on this member, Sean could hear a long whine in the next stall: Ginga had come on James's cock. He turned off Kenga's ring and put his trousers on.

James was sitting on the stool and had Ginga between his legs, cleaning his sperm. Sean had an idea:

"Do you want to try a male's tongue on your cock? I have begun to train Kafu to do it."

James was a bit surprised, but he agreed. Every new sensation was welcome to him.

They went over to Kafu's stall; James's member was out from his pants, still wet with his cum.

"Kafu! Come here, you have work to do!"

The young centaur stood up and came to meet his master.

"I want you to lick Dr. Wilkins's cock, he has just come out from Ginga."

Kafu hesitated a bit, but then a quick image flashed through his mind: the bad bug biting his sac, his bucking and prancing, and the acute pain that he had felt. He folded his front legs obediently and put the man's cock into his mouth.