resembled a cross between a bird and a lizard, its shape resembling a bird, as did tiny rudimentary wings and a long beak, while the scaly covering and the fact that it had four legs instead of two bore out the idea that it might be a lizard. Its huge birdlike beak was armed with three rows of long sharp teeth with which it was tearing at our captor. The purple amoeba was holding its assailant with a dozen of its thrown out feelers which were wrapped about the body and legs of the green horror. The whole battle was conducted in absolute silence.

"Now's our chance, Jim!" I cried. "Get away from here while that dragon has the amoeba busy!"

He jumped to the control levers of the flyer and pulled the starting switch well forward. The shock of the sudden start hurled me to the floor, but from where I fell I was able to watch the battle on the plain below us. It raged with uninterrupted fury and I felt certain of our escape when, with a shock which hurled both Jim and me to the ceiling, the flyer stopped. We fell back to the floor and I reflected that it was well for us that the interior of the flyer was so well padded. Had it not been, our bones would have been broken a dozen times by the shocks to which we had been subjected.

"What now?" I asked as I painfully struggled to my feet.

"Another of those purple amoebas," replied Jim from the vantage point of a window. "He's looking us over as if he were trying to decide whether we are edible or not."

I joined him at the window. The thing which had us was a replica of the monster we had left below us engaged in battle with the green dragon which had attacked it. The same indefinite and ever changing outline was evident, as well as the four huge eyes. The thing regarded us for a moment and slowly moved us up against its bulk until we touched it. Deeper and deeper into the mass of the body we penetrated until we were in a deep cavern with the light coming to us only from the entrance. I watched the entrance and horror possessed my soul.

"The hole's closing. Jim!" I gasped. "The thing is swallowing us!"

"I expected that," he replied grimly. "The amoeba has no mouth, you know. Nourishment is passed into the body through the skin, which closes behind it. We are a modern version of Jonah and the whale, First Mortgage."

"Well, Jonah got out," I ventured.

"We'll try to," he replied. "When that critter swallowed us, he got something that will prove pretty indigestible. Let's try to give him a stomach ache. I don't suppose that a machine-gun will affect him, but we'll try it."

"I didn't know that you had any guns on board."

"Oh yes, I've got two machine-guns. We'll turn one of them loose, but I don't expect much effect from it."

He moved over to one of the guns and threw off the cover which had hidden it from my gaze. He fed in a belt of ammunition and pulled his trigger. For half a minute he held it down, and two hundred and fifty caliber thirty bullets tore their way into space. There was no evidence of movement on the part of our host.

"Just as I thought," remarked Jim as he threw aside the empty belt and covered the gun again. "The thing has no nervous organization to speak of and probably never felt that. We'll have to rig up a disintegrating ray for him."

"What?" I gasped.

"A disintegrating ray," he replied. "Oh yes, I know how to make the fabulous 'death ray' that you journalists are always raving about. I have never announced my discovery, for war is horrible enough without it, but I have generated it and used it in my work a number of times. Did it never occur to you that the rocket motor is built on a disintegrating ray principle?"

"Of course it is, Jim. I never thought of it in that light before, but it must be. How can you use it? The discharge from the motors is a harmless stream of energy particles."

"Instead of turning the ray into powdered aluminum and breaking it down, what is to prevent me from turning it against the body of our captor and blasting my way out?"

"I don't know."

"Well, nothing is. I'll have to modify one of the motors a little, but it's not a hard job. Get some wrenches from the tool box and we'll start."

An hour of hard work enabled us to disconnect one of the reserve bow motors and, after the modifications Jim had mentioned, turn the ray out through the port through which the products of disintegration were meant to go. When we had bolted it in place with an improvised coupling, Jim opened the vitriolene screen which held in our air and turned to his control board.

"Here goes," he said.

He pulled the lever to full power and with a roar which almost deafened us in the small flyer, the ray leaped out to do its deadly work. I watched through a port beside the motor. There was a flash of intense light for an instant and then the motor died away in silence. A path to freedom lay open before us. Jim started one of the stern motors and slowly we forced our way through the hole torn in the living mass. When we were almost at the surface, he threw in full power and we shot free from the amoeba and into the open. Again we were stopped in midair and drawn back toward the huge bulk. The eyes looked at us and we were turned around. As the ray swung into a position to point directly toward one of the eyes, Jim pulled the controlling lever. With the flash of light which ensued, the eye and a portion of the surrounding tissue disappeared. The amoeba writhed and changed shape rapidly, while flashes of brilliant crimson played over the remaining eyes. Again the ray was brought into play and another of the eyes disappeared. This was evidently enough for our captor, for it suddenly released us and instantly we started to fall. Jim caught the control levers and turned on our power in time to halt us only a few feet above the plain toward which we were falling. We were close to the point whence we had started up and we could see that the battle below us was still raging.

The green dragon was partially engulfed by the amoeba, but it still relentlessly tore off huge chunks and devoured them. The amoeba was greatly reduced in bulk but it still fought gamely. Even as we approached the dragon was evidently satiated, for it slowly withdrew from the purple bulk and back away. Long feelers shot out from the amoeba's bulk toward the dragon but they were bitten off before they could grasp their prey.

"Let's get away from here, Jim," I cried, but I spoke too late. Even as the words left my mouth the green dragon saw us and raised itself in the air, and with gaping jaws launched itself at us. It took Jim only a moment to shoot the flyer up into space, and the charge passed harmlessly beneath us. The dragon checked its headway and turned again toward us.

"Use the machine-gun, Pete!" cried Jim. "I've got to run the ship."

I threw the cover off the gun and fed in a fresh belt of ammunition. As the green monster dashed toward us I hastily aligned the gun and pulled the trigger. My aim was good and at least fifty of the bullets plowed through the approaching bulk before Jim dropped the ship and allowed it to pass above us. Again the dragon turned and charged, and again I met it with a hail of bullets. They had no apparent effect and Jim dropped the ship again and let the huge bulk shoot by above us. Twice more the dragon rushed but the last rush was less violent than had been the first three.

"The bullets are affecting him, Pete!" cried Jim as he shot the flyer upward. "Give him another dose!"

I hastily fed in another belt, but it was not needed. The dragon rushed the fifth time, but before it reached us its velocity fell off and it passed harmlessly below us and