anything like it."

"What kind of pathology did you find?" Tiger wanted to know.

"Nothing," Dal said. "Nothing at all. I did autopsies on the six that
you brought up here and made slides of every different kind of tissue I
could find. The anatomy is perfectly clear cut, no objections there.
These people are very similar to Earth-type monkeys in structure, with
heart and lungs and vocal cords and all. But I can't find any reason why
they should be dying. Any luck with the cultures?"

Jack shook his head glumly. "No growth on any of the plates. At first I
thought I had something going, but if I did, it died, and I can't find
any sign of it in the filtrates."

"But we've got to have _something_ to work on," Tiger said desperately.
"Look, there are some things that always measure out the same in _any_
intelligent creature no matter where he comes from. That's the whole
basis of galactic medicine. Creatures may develop and adapt in different
ways, but the basic biochemical reactions are the same."

"Not here, they aren't," Dal said. "Take a look at these tests!"

They carried the heap of notes they had collected out into the control
room and began sifting and organizing the data, just as a survey team
would do, trying to match it with the pattern of a thousand other
living creatures that had previously been studied. Hours passed, and
they were farther from an answer than when they began.

Because this data did not fit a pattern. It was _different_. No two