The effect of cadmium and mercury on gemmule formation and gemmosclere morphology in Ephydatia fluviatilis. |
The outer coat forms a kind of mantle by means of the skirts of which the gemmule is fastened to the support of the sponge. |
We can easily conceive a being so small, that a gemmule would be to it as large as St. Paul's would be to us. |
The terminal growing bud of the axis is called the plumule or gemmule, and represents the ascending axis. |