The main differences between emitter and collector are doping concentration and size. The emitter is heavily doped, while the collector is lightly doped. You could try to swap them, but you'll get a very low \$H_{FE}\$, probably even less than 1.
Image Credit: Photo: Oxmoor House. SEASON: Although available year-round, eggplant is at its peak from July to October. CHOOSING: When selecting, look for eggplants with firm, glossy skin. Size and color vary widely among types, but the eggplant should feel heavy. Avoid those with wrinkled skin, soft spots, or brown patches.
It's best to start cool-season crops such as lettuce, cabbage, kale and chard in late February to early March in western Oregon, said Weston Miller, a horticulturist with the Oregon State University Extension Service. Warm-season crops such as tomatoes and peppers should be started in late March to early April.