NASHVILLE — A monarch butterfly’s chrysalis is one of the most beautiful things in nature. Bright emerald green and flecked with gold, it is an exquisite jewel that contains within it an even more exquisite promise.

The day before a monarch emerges, its chrysalis turns dark, almost black, but if you hold a light up to it, you can see the shape of vivid orange wings inside. The wings are lined with black veins like stained-glass windows in a cathedral. They are still tightly folded, but they hold, in miniature, the shape of an adult butterfly’s wings. At this stage, it’s possible to tell the butterfly’s gender even before it emerges from the chrysalis, just by looking at the thickness of those black veins framing the folded wings.

I’ve been trying to cultivate monarchs in my family room for two summers now, with mixed results. Last year few of my mail-order caterpillars formed a chrysalis and none survived to become a butterfly. This year I’ve had better luck: After watching a monarch female lay eggs on the milkweed in my own garden — not once but twice this season — I brought a few eggs indoors to raise safe from predators. I released seven healthy butterflies in June and four more last week, a perfect record of egg-to-butterfly survival. But I don’t know how many eggs hatched in the garden, or how many of those that hatched survived. Even with their bright yellow stripes, monarch caterpillars are skilled at camouflage.

As a species, the Eastern monarch — an iconic butterfly that migrates 3,000 miles every year — is in serious trouble. A changing climate is part of the problem, imperiling the monarch’s Mexican wintering grounds and spawning extreme weather events that can destroy millions of migrating butterflies. And pesticide drift can poison caterpillars even when they aren’t the targeted pest.