How does the structure of the gills allow for the production of so many spores?

In gilled mushrooms, gills are used to maximize spore production. Gills of some mushrooms are folded and crowded to obtain maximum spore production. Other gills, spread towards the outer cap which gives way to new gill growth in between gills which is called partial gill. Some of the mushrooms grow gills in layers too. 

Called for cell.