Malcolm nodded.
“What’d you use, Ian, your pocketknife?” “Something like that.”
“All right. Let’s deal with the tissue sample first.” The slide changed; Malcolm saw a microscopic view. “This is a gross histologic section through the superficial epidermis. Those patchy, ragged gaps are where the postmortem necrotic change has eroded the skin surface. But what is interesting is the arrangement of epidermal cells. You’ll notice the density of chromatophores, or pigment-bearing cells. In the cut section you see the difference between melanophores here, and allophores, here. The overall pattern is suggestive of a lacerta or amblythynchtis.”
“You mean a lizard?” Malcolm said.
“Yes,” she said. “It looks like a lizard-though the Picture is not entirely consistent.” She tapped the left side of the screen. “You see this one cell here, which has this slight rim, in section? We believe that’s muscle. The chromatophore could open and close. Meaning that this animal could change color, like a chameleon. And over here you see this large oval shape, with a pale center? That’s the pore of a femoral scent gland. There is a waxy substance in the center which we are still analyzing. But our presumption is that this animal was male, since only male lizards have femoral glands.”
“I see,” Malcolm said.
She changed the slide, Malcolm saw what looked like a close-up of a sponge. “Going deeper. Here we see the Structure of the subcutaneous layers. Highly distorted, because of gas bubbles from the clostridia infection that bloated the animal. But you can get a sense of the vessels – see one here – and another here – which are surrounded by smooth muscle fibers. This is not characteristic of lizards, In fact, the whole appearance of this slide is wrong for lizards, or reptiles of any sort.”
“You mean it looks warm-blooded.”
“Right,” Gelman said. “Not really mammalian, but perhaps avian. This could be, oh, I don’t know, a dead pelican. Something like that.”
“Uh-huh.”
“Except no pelican has a skin like that.”
“I see,” Malcolm said.
“And there s no feathers.”
“Uh-huh.”
“Now,” Gelman said, “we were able to extract a minute quantity of blood from the intra-arterial spaces. Not much, but enough to conduct a microscopic examination. Here it is.”
The slide changed again. He saw a jumble of cells, mostly red cells, and an occasional misshapen white cell. It was confusing to look at.
“This isn’t my area, Elizabeth,” he said.
“Well, I’ll just give you the highlights,” she said. “First of all, nucleated red cells. That’s characteristic of birds, not mammals. Second, rather atypical hemoglobin, differing in several base pairs from other lizards. Third, aberrant white-cell structure. We don’t have enough material to make a determination, but we suspect this animal has a highly unusual immune system.
“Whatever that means,” Malcolm said, with a shrug.
“We don’t know, and the sample doesn’t give us enough to find out. By the way, can you get more?”
“I might be able to,” he said.
“Where, from Site B?”
Malcolm looked puzzled. “Site B?”
“Well, that’s what’s embossed on the tag.” She changed the slide. “I must say, Ian, this tag is very interesting. Here at the zoo, we tag animals all the time, and we’re familiar with all the ordinary commercial brands sold around the world. Nobody’s seen this tag before. Here it is, magnified ten times. The actual object is roughly the size of your thumbnail. Uniform plastic outer surface, attaches to the animal by a Teflon coated, stainless-steel clip on the other side. It’s a rather small clip, of the kind used to tag infants. The animal you saw was adult?”
“Presumably.”
“So the tag was probably in place for a while, ever since the animal was young,” Gelman said. “Which makes sense, considering the degree of weathering. You’ll notice the pitting on the surface. That’s very Unusual. This plastic is Duralon, the stuff they use to make football helmets. It’s extremely tough, and this pitting can’t have occurred through simple wear.”
“Then what?”
“It’s almost certainly a chemical reaction, such as exposure to acid, perhaps in aerosol form.”
“Like volcanic fumes?” Malcolm said.
“That could do it, particularly in view of what else we’ve learned. You’ll notice that the tag is rather thick – actually, it’s nine millimeters across. And it’s hollow.”