蠶 / 蚕

The Chinese word cán refers specifically to the domesticated silkworm, Bombyx mori, which has been selectively bred for so long that it cannot survive in the wild. The oldest known silk fabric dates to approximately 3630 BCE, found at the Hemudu site in Zhejiang Province. The insect was domesticated even earlier. Bombyx mori has lost the ability to fly, and its larvae are so dependent on human care that they will starve on a mulberry branch rather than move to find fresh leaves. This is not a wild animal. It is a product of 5,000 years of selective breeding.

The Silk Road — the 4,000-mile trade network linking China to Rome — was named for the commodity that justified its existence. Silk reached Rome by the first century BCE, and Pliny the Elder complained that Roman women's taste for silk was draining the empire's gold reserves. The Roman word for silk was sericum, from Seres, the Latin name for China — 'the silk people.' But how silk was made remained a Chinese state secret. The penalty for exporting silkworms or mulberry seeds was death.

The secret was broken around 552 CE, according to the historian Procopius. Two Nestorian monks smuggled silkworm eggs out of China in hollow bamboo canes, delivering them to the Byzantine Emperor Justinian I in Constantinople. Whether this story is precisely true is debated, but silk production did reach the Byzantine Empire in the sixth century and spread to Italy, Spain, and France over the following centuries. Lyon became the silk capital of Europe by the 1600s.

The English word silkworm is a compound so literal it needs no explanation: a worm that makes silk. The Chinese cán and the English silkworm name the same domesticated insect, but the Chinese word carries 5,000 years of cultural weight. In Chinese, the silkworm is associated with diligence, sacrifice (it dies to produce silk), and the goddess Leizu, who according to legend discovered silk when a cocoon fell into her tea around 2700 BCE.