metaxylem

metaxylem

1. It consists of the protoxylem (formed first) and metaxylem.

包括原生木质部（最早形成的）和后生木质部。

2. It is found in protoxylem and first metaxylem tracheids and vessels.

可在原生木质部和初始后生木质部的管胞和导管中见到。

3. metaxylem initials

后生木质部原始细脂

4. These cells began to devise, then developed into aloin cells through enlargement of volume and vacuolization with the differentiation of metaphloem and metaxylem.

在后生韧皮部和木质部发育成熟过程中，这些细胞体积逐渐增大，并液泡化，发育成为大型薄壁细胞（芦荟素细胞），位于筛管外侧。