"are colored patterns or images made in a glass cane that are revealed when the cane is cut into thin cross-sections. Murrine can be made in infinite designs from simple circular or square patterns to complex detailed designs to even portraits of people. One familiar style is the flower or star shape which, when used together in large numbers from a number of different canes, is called millefiori.

Murrine production first appeared in the Middle East more than 4,000 years ago and was revived by Venitian Glassartists on Murano in the early 16th century.

Once murrine have been made, they can be incorporated into a glass vessel or sculpture in several ways. A number of murrine may be scattered, more or less randomly, on a marver (steel table) and then picked up on the surface of a partially-blown glass bubble. Further blowing, heating, and shaping on the marver will incorporate the murrine completely into the bubble, creating a random arrangement of murrine in the vessel or sculpture being blown."

https://en.wikipedia.org/wiki/Murrine