available. "You handle anatomy and pathology," Jack told Dal at the
beginning. "You can get the picture five times as fast as I can, and
your pathology slides are better than most commercial ones. I can do the
best job on the cultures, once I get the growth media all set up."

Bit by bit they divided the labor, checking in with Tiger by radio on
the results of the isotopes studies he was running on the planet's
surface. Bit by bit the data was collected, and Earthman and Garvian
worked more closely than ever before as the task that faced them
appeared more and more formidable.

But the results of their tests made no sense whatever. Tiger returned to
the ship after forty-eight hours with circles under his eyes, looking as
though he had been trampled in a crowd. "No sleep, that's all," he said
breathlessly as he crawled out of his decontaminated pressure suit. "No
time for it. I swear I ran those tests a dozen times and I still didn't
get any answers that made sense."

"The results you were sending up sounded plenty strange," Jack said.
"What was the trouble?"

"I don't know," Tiger said, "but if we're looking for a biological
pattern here, we haven't found it yet as far as I can see."

"No, we certainly haven't," Dal exploded. "I thought I was doing
something wrong somehow, because these blood chemistries I've been doing
have been ridiculous. I can't even find a normal level for blood sugar,
and as for the enzyme systems...." He tossed a sheaf of notes down on
the counter in disgust. "I don't see how these people could even be
alive, with a botched-up metabolism like this! I've never heard of