as entirely out of practice in
speaking to please a female.

"Thanks," she said wryly, and the conversation ended.

Somehow, the brief talk with her restored his perspective. Once again
she was his assistant, and the significance of her as a woman faded. She
was a dedicated physician like himself. In another few years, she would
find a residency of her own. She had no more inclination to knock off
and become a woman than he had to squander his time and energy on
attaining the status of family man.

* * * * *

It was with mounting admiration that he followed her new project in
examining blood samples. As they came up from the clinic, she sorted the
specimen tubes at once, putting a tiny snip of yellow Scotch tape under
the label of each sample that belonged to a patient with the new
undiagnosed disorder.

Then, after the requested hemoglobin, blood sugar and other standard
tests had been run, she retrieved the samples from the technicians,
grouped them in a special rack and devoted every spare minute to further
examination.

She centrifuged, precipitated, filtered and stained over and over, using
every qualitative procedure in the book. Murt signed her requisitions
for exotic reagents and rare stains. He helped her balance out the large
centrifuge to get the maximum r.p.m. from it. He let her use the most
costly of the fine-porosity filters.

He had little hope of success, but it was good practice for her. She was
required to identify every organism she found, bone up on its known
effects, then determine that it could not cause the symptoms reported.

She did all this without impairing her usefulness to Murt. When he
needed her, she was at his side, dissecting, taking down notes,
preparing delicate sections and checking slides before they came to him.

In several weeks, she exhausted all known tests on the first samples.
After lunch one day, she turned her palms up. "_Nichts da!_" she said,
pulling a mashed cigarette from the huge pocket of her white smock.

He glanced at her and swiveled to stare out the window. It was part of
his tight campaign to prevent a disastrous recurrence of the emotional
tempest he had suffered the day she had begun this research.

"It was a nice brush-up on your bacteriology," he said. "Have you saved
the filtrates?"

"Yes, of course. Did I overlook anything?"

"Nothing that we could do here, but there's an electron microscope
downtown at Ebert In