The spiral vessel in its early stages has bands of peripheral cytoplasm which precede the spiral markings, and which have the same arrangement, and become the basis of the lignified spiral. The position of the cytoplasmic bands is determined by rows of vacuoles in the cytoplasm immediately preceding and during the formation of the bands. The position of the bands of the annular vessel is also determined by vacuoles. The young cell of the metaxylem also has vacuolated peripheral cytoplasm which precedes the formation of its markings.