"I believe so," Dr. Cruz said. "I have given her another dose of steroids, and her breathing is much easier. And you can see the edema in her arm is greatly reduced."

Mike Bowman said, "About those bites…"

"We have no identification yet," the doctor said. "I myself haven't seen bites like that before. But you'll notice they are disappearing. It's already quite difficult to make them out. Fortunately I have taken photographs for reference. And I have washed her arm to collect some samples of the sticky saliva-one for analysis here, a second to send to the labs in San Jose, and the third we will keep frozen in case it is needed. Do you have the picture she made?"

"Yes," Mike Bowman said. He handed the doctor the sketch that Tina had drawn, in response to questions from the admitting officials.

"This is the animal that bit her?" Dr. Cruz said, looking at the picture.

"Yes," Mike Bowman said. "She said it was a green lizard, the size of a chicken or a crow."

"I don't know of such a lizard," the doctor said. "She has drawn it standing on its hind legs…"

"That's right," Mike Bowman said. "She said it walked on its hind legs."

Dr. Cruz frowned. He stared at the picture a while longer. "I am not an expert. I've asked for Dr. Guitierrez to visit us here. He is a senior researcher at the Reserva Biologica de Carara, which is across the bay. Perhaps he can identify the animal for us."

"Isn't there someone from Cabo Blanco?" Bowman asked. "That's where she was bitten."

"Unfortunately not," Dr. Cruz said. "Cabo Blanco has no permanent staff, and no researcher has worked there for some time. You were probably the first people to walk on that beach in several months. But I am sure you will find Dr. Guitierrez to be knowledgeable."

Dr. Guitierrez turned out to be a bearded man wearing khaki shorts and shirt. The surprise was that he was American. He was introduced to the Bowmans, saying in a soft Southern accent, "Mr. and Mrs. Bowman, how you doing, nice to meet you," and then explaining that he was a field biologist from Yale who had worked in Costa Rica for the last five years. Marty Guitierrez examined Tina thoroughly, lifting her arm gently, peering closely at each of the bites with a penlight, then measuring them with a small pocket ruler. After a while, Guitierrez stepped away, nodding to himself as if he had understood something. He then inspected the Polaroids, and asked several questions about the saliva, which Cruz told him was still being tested in the lab.

Finally he turned to Mike Bowman and his wife, waiting tensely. "I think Tina's going to be fine. I just want to be clear about a few details," he said, making notes in a precise band. "Your daughter says she was bitten by a green lizard, approximately one foot high, which walked upright onto the beach from the mangrove swamp?"

"That's right, yes."

"And the lizard made some kind of a vocalization?"

"Tina said it chirped, or squeaked."

"Like a mouse, would you say?"

"Yes."

"Well, then," Dr. Guitierrez said, "I know this lizard." He explained that, of the six thousand species of lizards in the world, no more than a dozen species walked upright. Of those species, only four were found in Latin America. And judging by the coloration, the lizard could be only one of the four. "I am sure this lizard was a Basiliscus amoratus, a striped basilisk lizard, found here in Costa Rica and also in Honduras. Standing on their hind legs, they are sometimes as tall as a foot."

"Are they poisonous?"

"No, Mrs. Bowman. Not at all." Guitierrez explained that the swelling in Tina's arm was an allergic reaction. "According to the literature, fourteen percent of people are strongly allergic to reptiles," he said, "and your daughter seems to be one of them."

"She was screaming, she said it was so painful."

"Probably it was," Guitierrez said. "Reptile saliva contains serotonin, which causes tremendous pain." He turned to Cruz. "Her blood pressure came down with antihistamines?"

"Yes," Cruz said. "Promptly."

"Serotonin," Guitierrez said. "No question."

Still, Ellen Bowman remained uneasy. "But why would a lizard bite her in the first place?"

"Lizard bites are very common," Guitierrez said. "Animal handlers in zoos get bitten all the time. And just the other day I heard that a lizard had bitten an infant in her Crib in Amaloya, about sixty miles from where you were. So bites do occur. I'm not sure why your daughter had so many bites. What was she doing at the time?"

"Nothing. She said she was sitting pretty still, because she didn't want to frighten it away."

"Sitting pretty still," Guitierrez said, frowning. He shook his head. "Well. I don't think we can say exactly what happened. Wild animals are unpredictable."

"And what about the foamy saliva on her arm?" Ellen said. "I keep thinking about rabies…"

"No, no," Dr. Guitierrez said. "A reptile can't carry rabies, Mrs. Bowman. Your daughter has suffered an allergic reaction to the bite of a basilisk lizard. Nothing more serious."

Mike Bowman then showed Guitierrez the picture that Tina had drawn. Guitierrez nodded. "I would accept this as a picture of a basillsk lizard," he said. "A few details are wrong, of course. The neck is much too long, and she has drawn the hind legs with only three toes instead of five. The tall is too thick, and raised too high. But otherwise this is a perfectly serviceable lizard of the kind we are talking about."

"But Tina specifically said the neck was long," Ellen Bowman insisted. "And she said there were three toes on the foot."

"Tina's pretty observant," Mike Bowman said.

"I'm sure she is," Guitierrez said, smiling. "But I still think your daughter was bitten by a common basilisk amoratus, and had a severe herpetological reaction. Normal time course with medication is twelve hours. She should be just fine in the morning."

In the modern laboratory in the basement of the Clinica Santa Maria, word was received that Dr. Guitierrez had identified the animal that had bitten the American child as a harmless basilisk lizard. Immediately the analysis of the saliva was halted, even though a preliminary fractionation showed several extremely high molecular weight proteins of unknown biological activity. But the night technician was busy, and he placed the saliva samples on the holding shelf of the refrigerator.

The next morning, the day clerk checked the holding shelf against the names of discharged patients. Seeing that BOWMAN, CHRISTINA L. was scheduled for discharge that morning, the clerk threw out the saliva samples. At the last moment, he noticed that one sample had the red tag which meant that it was to be forwarded to the university lab in San Jose. He retrieved the test tube from the wastebasket, and sent it on its way.

"Go on. Say thank you to Dr. Cruz," Ellen Bowman said, and pushed Tina forward.

"Thank you, Dr. Cruz," Tina said. "I feel much better now." She reached up and shook the doctor's band. Then she said, "You have a different shirt."

For a moment Dr. Cruz looked perplexed; then he smiled. "That's right, Tina. When I work all night at the hospital, in the morning I change my shirt."

"But not your tie?"

"No. Just my shirt."

Ellen Bowman said, "Mike told you she's observant."

"She certainly is." Dr. Cruz smiled and shook the little girl's band gravely. "Enjoy the rest of your holiday in Costa Rica, Tina."

"I will."

The Bowman family had started to leave when Dr. Cruz said, "Ob, Tina, do you remember the lizard that bit you?"

"Uh-huh."

"You remember its feet?"

"Uh-huh."

"Did it have any toes?"

"Yes."

"How many toes did it have?"

"Three," she said.

"How do you know that?"

"Because I looked," she said. "Anyway, all the birds on the beach made marks in the sand with three toes, like this." She held up her hand, middle three fingers spread wide. "And the lizard made those kind of marks in the sand, too."

"The lizard made marks like a bird?"

"Uh-huh," Tina said. "He walked like a bird, too. He jerked his head like this, up and down." She took a few steps, bobbing her head.

After the Bowmans had departed, Dr. Cruz decided to report this conversation to Guitierrez, at the biological station.

"I must admit the girl's story is puzzling," Guitierrez said. "I have been doing some checking myself. I am no longer certain she was bitten by a basilisk. Not certain at all."

"Then what could it be?"

"Well," Guitierrez said, "let's not speculate prematurely. By the way, have you heard of any other lizard bites at the hospital?"

"No, why?"

"Let me know, my friend, if you do."

Marty Guitierrez sat on the beach and watched the afternoon sun fall lower in the sky, until it sparkled harshly on the water of the bay, and its rays reached beneath the palm trees, to where he sat among the mangroves, on the beach of Cabo Blanco. As best he could determine, he was sitting near the spot where the American girl had been, two days before.

Although it was true enough, as he had told the Bowmans, that lizard bites were common, Guitierrez had never heard of a basilisk lizard biting anyone. And he had certainly never heard of anyone being hospitalized for a lizard bite. Then, too, the bite radius on Tina's arm appeared slightly too large for a basilisk. When he got back to the Carara station, he had checked the small research library there, but found no reference to basilisk lizard bites. Next he checked International BioSciences Services, a computer database in America, But he found no references to basilisk bites, or hospitalization for lizard bites.

He then called the medical officer in Amaloya, who confirmed that a nine-day-old infant, sleeping in its crib, had been bitten on the foot by an animal the grandmother-the only person actually to see it-claimed was a lizard. Subsequently the foot had become swollen and the infant had nearly died. The grandmother described the lizard as green with brown stripes. It had bitten the child several times before the woman frightened it away.