They
are coconuts! Real coconuts have a thick green layer surrounding the usual brown
shell. The green layer helps the coconuts float, should they fall in the water.
Then they can float to new places, and start new coconut palm trees. The white
coconut "meat" is good to eat. There is also a liquid inside, that is good to
drink. It is called "milk"! The vendor hacks the top off with a
machete, and sticks in a straw.