What is this area?

What are these outer cells?

What are these fingerlike projections?

What are these?

What is this?

What is this whole thing not fingers?

What is this membrane?

What are these?

What is this outermost layer?

What is this entire thing?

What is this?

What are these?

What is this?

What is this inner membrane?

What is this?

What is this space?

What is this?

What is this?

What is this?

What is this space?