vitello-, vitell-

The part of the ovary in some invertebrates; for example, certain flatworms, that produces yolk-filled cells providing nourishment to the developing eggs: "The students used a fine scalpel to dissect the large flatworm in order to observe its vitellarium."

Yolk producing or producing yolk.

In biochemistry, protein in the yolk of an egg.

1. Colored like the yolk of an egg; deep-yellow with a tinge of red.
2. In early use specifically of bile.

The membrane that encloses a fertilized egg.

The yolk of an egg. The word vitellus was first used in the sense "yolk of an egg", by Aulus Cornelius Celsus, a Roman physician and writer of the early first century.