The melting pans are generally circular vessels, fitted with a perforated false bottom, on which the sugar to be melted is dumped.
The wall between them is perforated, giving passage to coarse strands of protoplasm.
The bottom of a crucible is perforated by a pipe which projects into the crucible to about two-thirds of its height.
With another form of gas stove coke is used in place of the perforated asbestos; the fire is started with the gas, which, when the coke is well alight, may be dispensed with, and the fire kept up with coke in the usual way.
When the bud is nearly complete, the body-wall of the parent immediately below it becomes perforated, placing the coelenteric cavity of the parent in secondary communication with that of the bud (H), doubtless for the better nutrition of the latter.