This is the second in a series of "Mary Lou Quizzes" that will run all semester.

The Case of the Saguaro Measles

..... Recently Mary Lou and her class* had presented their chloroplast/photosynthesis findings at a conference in San Diego, and were now beginning their trip back to Virginia. ..They had stopped at the blue-roofed Harvey House in the Mojave Desert railroad town of Barstow CA for lunch. ..While the gang looked around the gift shop, Mary Lou got it into her head that this might be the last chance for her to be able to buy local souvenirs. ..She bought a 'baby' saguaro cactus, and a small bag of borax such as was brought in by the 40-mule teams a century ago from nearby Death Valley.

..... When they were on the road again, her high school whiz-kid brother Jason noticed that her cactus had a number of small brown spots on it. ..The prickly plant was set in the rear window, and this brown measles became the talk of the day's drive, and was only interrupted as they passed the world's largest thermometer in a small town called Baker CA, which lay on the alkali flats of a sister to Death Valley. ..The temperature was a sizzling 116°F, which prompted them to stop at Bun Boy for some cooling drinks. ..They were relieved to safely make it to Las Vegas and check into the Imperial Palace (first night free; each following night is $10 per person). ..Of course, they were all excited to see the exploding 'volcano' in front of the Mirage across the street, and emperor and his queen at Caesar's Palace, and the ship battle at Treasure Island, and Bugsy's Flamingo nextdoor, and Š, and Š

..... During the next few days, while Prof. Bengston, Cheryl, Jimmy, and Mary Lou exercised their arms (on machines) and legs (an awful lot of walking) on the Vegas "Strip", the underage Jason and his overalled friend Wilbie made themselves at home at the Ethyl M's (Mars) Candy Factory, which, they noticed had not only a small chocolate and gift shop (with measled saguaros), but also a magnificent cactus garden surrounding the parking lot. ..Wilbie was the first to notice that many of the permanently planted saguaros also had the brown measles - but only on the north side, or on those that were growing in the shade of mesquite or other bushes. .. Somewhat later, a quick inspection of Mary Lou's little plant revealed that the spots were fading.

..... When they had all gotten back together, and were cracking crab's legs at the $5.95 buffet at the Stardust (a $2-roll of slot machine quarters is rebated at the end of the meal!), the conversation turned to the brown measles. ..What might be curing the measles? ..How would you use the UNLV biology facilities to test your hypothesis supposing you could stay over for several more days? ..(UNLV has facilities about those of Millington Hall at W&M.)