Describe the internal structure of a microsporangium.

$A$ typical microsporangium appears near circular in outline.
It is generally surrounded by four wall layers: epidermis,endothecium,middle layers,and the tapetum.
The outer three wall layers (epidermis,endothecium,and middle layers) perform the function of protection and help in the dehiscence of the anther to release the pollen grains.
The innermost wall layer is the tapetum. It nourishes the developing pollen grains.
Cells of the tapetum possess dense cytoplasm and generally have more than one nucleus.
When the anther is young,a group of compactly arranged homogenous cells called the sporogenous tissue occupies the centre of each microsporangium.