A flattened cake of viscous glass-enamel is welded on to one side of the mass of glass after it has been hollowed by blowing.
The external openings in the male are armed with a pair of hollowed spines.
The mass of glass is rolled on a polished slab of iron, the " marvor," to solidify it, and it is then slightly hollowed by blowing.
Under the new system the bowl is fashioned by blowing the slightly hollowed mass of glass into a mould.
In the American button-bush the heads are globular, in some species of teazel elliptical, while in scabious and in composite plants, as sunflower, dandelion, thistle, centaury and marigold, they are somewhat hemispherical, with a flattened, slightly hollowed, or convex disk.
