To illustrate the selfless nature of the five aggregates the Buddha gives certain similies.
He says:

(a)The body is like a lump of foam - seems solid but when crushed turns out to be a hollow.
(b)Feeling is like a bubble - bubbles on water just arise and break up and show themselves to be empty.
(c)Perception is like a mirage. A mirage appears but when we examine it we don't find anything substantial.
(d)Formations are like the trunk of a banana tree. Just rolls of tissue within rolls and rolls without hard wood.
(e)Consciousness is like a magical illusion.It appears but has no substance.