The latter, known as the calymma, is traversed by a number of water-vesicles or vacuoles.
If vacuoles have any special function, it is an unimportant one.
Their appearance is that of vacuoles, and with these they are probably to be compared.
This is filled with a granular protoplasm, in which vacuoles are formed.
When it desires to make itself heavier and sink, the vacuoles ...