Lucky for Colby that Betsy Stark Champlin '65 was available when Allan Scott, Dana Professor of Biology, emeritus, needed a fill-in for his class back in 1971. For Champlin, a senior teaching associate, that one-time $50 gig has evolved into a 28-year affiliation with the Biology Department.     Similarly, Jean McIntyre's arrival at Colby coincided with a need for help in the science program. A senior teaching associate since 1976, McIntyre stepped into the Chemistry Department as the College's science program was growing.     Champlin and McIntyre, along with Bruce Rueger in geology and Tim Christensen in biology, represent nearly 85 years of experience in Colby's laboratories. In all, there are 11 teaching associates and assistants, whose roles should not be confused with graduate students' roles, which have given the title "teaching assistant" a different meaning and even a negative connotation at some universities. According to Colby faculty who rely on them, these are crucial colleagues whose knowledge and skills complement their own. "We could not do what we do without them, quite frankly," said Paul Greenwood, associate professor of biology. "We take pride in the fact that we don't have to limit the number of classes we offer; we couldn't do that without the T.A.'s."     Some T.A.'s conduct their own research and publish their own scholarship. Two years ago Rueger received significant media coverage for his work on the effects of bird migration on the sediment found in lakes of Bermuda.     T.A.'s at Colby help faculty with everything from equipment organization to grading. They run lab sessions, coordinate student projects and provide one-on-one instruction. "I often have students ask me if they can have the same T.A. when they move from one lab to a new one," Greenwood said.     "What makes a great T.A. is their approachability and availability," said Junko Goda '01. "They have so much experience in dealing with frustrated students that they can really work with the student to solve a problem or understand a concept. They could teach the course themselves."     Teaching associates were practically unheard of when Champlin accompanied her husband, Leslie Brainerd Arey Professor of Biosciences Art Champlin, to Colby following a stint at the Jackson Laboratory and graduate work at the University of Rochester. She also had been a research assistant at Harvard and wasn't sure she would find a job at a small school like Colby, she says. Scott--whose class she stepped into--offered her part-time work. She has been a full-time T.A. since the early 1980s. "My senior year at Colby in 1965 there were ten biology majors," Champlin said. "This year we have eighty majors. Obviously, we don't have eight times as many faculty; the T.A.'s are here to help, especially in the labs where there is a lot of individual instruction."     McIntyre considers herself a teacher, not merely a teacher's aide. "I'm lucky--my role is basically teaching," she said. "I don't see this as a `put-your-time-in' kind of job." One recent weekend she wrote 14 letters of recommendation for students vying for graduate schools or summer internships.     "I find the freedom to make changes in our teaching very rewarding," McIntyre said, noting that experienced T.A.'s often are involved in curriculum development as well.     Champlin enjoys this opportunity to leave an imprint on the biology program. "That's where you get to use your brain," she said.     Colleen Burnham, a T.A. in psychology since 1992, says she was hired to handle "stats and rats," but her job has evolved and expanded. Her responsibility lies mostly in helping with labs, but she also counsels students, complements faculty instruction and fills a dozen other roles. "I'm involved in everything from French braids to grading papers," she said, laughing. "I've been known to cut a student's bangs before a lab session."     Dean of Faculty Ed Yeterian credits Burnham with holding together the department by serving its disparate needs. "Without Colleen we would have great difficulty providing our students with the level of laboratory and independent research experiences that we currently have," he said.     T.A.'s, while acknowledging that Colby has been a wonderful place to work, say there are frustrations associated with being "not quite faculty." McIntyre says that T.A.'s have few promotional opportunities, regardless of their years of service, because they lack faculty rank. And they chafe when they are compared to teaching assistants at graduate schools whose jobs, they say, bear no resemblance to their own. Ultimately, though, it's the students who make their jobs fulfilling.     "I feel lucky to have been able to share my passion and enthusiasm for genetics," Champlin said. "The students are exciting and appreciative. They are what makes the job rewarding."