Dr. Foster, who, with colleagues, has sequenced the genomes of about 30 samples of the fungus, said that while this explanation is likely, he will not consider it nailed down until the origin of the fungus in Europe is identified, which he thinks should occur in a year or so. But, he said, the major importance of full genome studies is to track how the fungus spreads in the United States. Because strains here are so similar, tracing the spread can be done only by using the tiny genetic differences that show up in comparing entire genomes.
      
Bat experts suspect that people who explore caves unwittingly carried the fungus to the United States from Europe, but they don't know for sure. Many caves in the eastern part of the country — all those on public land in Tennessee, for instance — have been closed to humans, but the fungus still spreads. The pattern, says Dr. Foster, is "consistent" with bats carrying it.
      
Although the fungus infects European bats, it does not cause the level of damage that it does to American bats, and one hope scientists have is to learn the nature of resistance to the fungus. Do European bats have different behaviors? Are there physiological changes? To answer some of these questions, researchers around the country, are catching, inspecting and banding bats, both to learn what is going on with the populations in general and to see if survivors are breeding and producing resistant offspring.
      
Nets or other traps are placed at cave entrances or other places where bats are roosting. This summer, Nate Fuller of Boston University captured little brown and big brown bats as they exited a barn in Massachusetts, where they had moved after hibernation to give birth and raise their pups. He measured them, took samples of oily material on their wings, and noted scarring on wings of survivors of white nose.
      
In Europe, Natalia Martinkova at the Academy of Sciences of the Czech Republic is studying how bats there respond to infection from the fungus. By studying what proteins genes produce during hibernation, she hopes to understand "what genes that might be involved in the immune response."
In the United States, researchers are pursuing many routes of study, including a project being undertaken by DeeAnn Reeder and Ken Field at Bucknell University that involves 150 little brown bats they are infecting with different doses of the fungus.
      
Dr. Reeder and Dr. Field will watch the progress of disease in different conditions and track immune activity with blood tests. "We don't fully understand the nature of immunity in hibernation," Dr. Field said.
      
For now, the finishing touches are being put on the Tennessee bat bunker. The mass of concrete and earth was under a baking late-summer sun during construction, and air-conditioners are needed to get the cave down to between 41 and 50 degrees by next week, when it is scheduled to be closed to humans.
      
Recorded calls of bats will be used to attract them to the cave. Gray bats could begin to gather in the area in prehibernation mode any time now; most will be hibernating by mid-November.        Win, lose or draw, the bet has been laid. And one cannot help think that the original Doc Holliday, known to gamble on occasion, and not one to avoid a showdown, would have approved.