It is evident that the outer envelope of the gonophore represents the ex-umbral ectoderm (ex.), and that the inner ectoderm lining the cavity represents the sub-umbral ectoderm of the free medusa.
The question is one intimately connected with the view taken as to the nature and individuality of polyp, medusa and gonophore respectively.
B and C, Two views of a female gonophore after t, Tentacles.
A, A male gonophore still enclosed in its ecto theca.
If the bud, however, is destined to give rise not to a free medusa, but to a gonophore, the development is similar but becomes arrested at various points, according to the degree to which the gonophore is degenerate.
The gonophore is now reduced to its simplest condition, known as the sporosac (fig.
Next the opening of the umbrella closes up completely and disappears, so that the sub-umbral cavity forms a closed space surrounding the manubrium, on which the gonads are developed; such a condition is seen in the male gonophore of Cladocoryne and in Garveia (fig.