By experiments that have been lately made, it appears that the natural silk from the silk worms can be obtained colored as desired by administering colored articles of food to silk worms just before they begin spinning their cocoons. The first experiments Were conducted with indigo, which was mixed in certain portions with the mulberry leaves, i serving the worms for food. The result of treatment was successful; blue cocoons were obtained. Small portions of bignonia chica having been added to the mulberry leaves, the silk-worms consumed the mixture and produced red colored silk.