foreign to her.
"Well," he said, "most of those things aren't so important. To sporulate is to create an oval body that has all the basic ingredients of the vegetative bacterium. The germ does that when it gets no fresh blood. Then, when the vampire host decomposes, these spores go flying out and seek new hosts. They find one, germinate--and one more system is infected."
She shook her head incredulously.
"Bacteriophages are inanimate proteins that are also created when the system gets no blood. Unlike the spores, though, in this case abnormal metabolism destroys the cells."
Quickly he told her about the imperfect waste disposal of the lymphatic system, the garlic as allergen causing anaphylaxis, the various vectors of the disease.
"Then why are we immune?" she asked.
For a long moment he looked at her, withholding any answer. Then, with a shrug, he said, "I don't know about you. As for me, while I was stationed in Panama during the war I was bitten by a vampire bat. And, though I can't prove it, my theory is that the bat had previously encountered a true vampire and acquired the vampiris germ. The germ caused the bat to seek human rather than animal blood. But, by the time the germ had passed into my sys?tem, it had been weakened in some way by the bat's system. It made me terribly ill, of course, but it didn't kill me, and as a result, my body built up an immunity to it. That's my theory, anyway. I can't find any better reason."
"But--didn't the same thing happen to others down there?"
"I don't know," he said quietly. "I killed the bat." He shrugged. "Maybe I was the first human it had attacked."
She looked at him without a word, her surveillance making Neville feel restive. He went on talking even though he didn't really want to.
Briefly he told her about the major obstacle in his study of the vampires.
"At first I thought the stake had to hit their hearts," he said. "I believed the legend. I found out that wasn't so. I put stakes in all parts of their bodies and they died. That made me think it was hemorrhage. But then one day--"
And he told her about the woman who had decomposed before his eyes.
"I knew then it couldn't be hemorrhage," he went on, feeling a sort of pleasure in reciting his discoveries. "I didn't know what to do. Then one day it came to me."
"What?" she asked.
"I took a dead vampire. I put his arm into an artificial vacuum. I punctured his arm inside that vacuum. Blood spurted out." He paused. "But that's all."
She stared at him.
"You don't see," he said.
"I--No," she admitted.
"When I let air back into the tank, the arm decomposed," he said.
She still stared.
"You see," he said, "the bacillus is a facultative saprophyte. It lives with or without oxygen; but with a difference. Inside the system, it is anaerobic and sets up a symbiosis with the system. The vampire feeds it fresh blood, the bacteria provides the energy so the vampire can get more fresh blood. The germ also causes, I might add, the growth of the canine teeth."
"Yes?" she said.
"When air enters," he said, "the situation changes instantaneously. The germ becomes aerobic and, instead of being symbiotic, it becomes virulently parasitic." He paused. "It eats the host," he said.
"Then the stake--" she started.
"Lets air in. Of course. Lets it in and keeps the flesh open so that the body glue can't function. So the heart has nothing to do with it. What I do now is cut the wrists deep enough so that the body glue can't work." He smiled a little. "When I think of all the time I used to spend making stakes!"
She nodded and, noticing the wineglass in her hand, put it down.
"That's why the woman I told you about broke down so rapidly," he said. "She'd been dead so long that as soon as air struck her system the germs caused spontaneous dissolution."
Her throat moved and a shudder ran down through her.
"It's horrible," she said.
He looked at her in surprise. Horrible? Wasn't that odd? He hadn't thought that for years. For him the word 'horror' had become obsolete. A surfeiting of terror soon made terror a cliché. To Robert Neville the situation merely existed as natural fact. It had no adjectives.
"And what about the--the ones who are still alive?" she asked.
"Well," he said, "when you cut their wrists the germ naturally becomes parasitic. But mostly they die from simple hemorrhage."
"Simple--"
She turned