The compound organism now develops two sets of inter-connected genitalia and becomes a Diplozoon.
In the remainder the segmentation involves primarily the genitalia and includes the integument, muscles and part of the excretory system.
This segregation of the germ cells and their independence of the intestinal sac is an indication that the origin of these cells is not coelomic nor enteric, and until we possess further information as to the evolution of the complex genitalia of the higher Turbellaria we cannot hope to understand the presence of such highly modified structures in animals of an otherwise low grade or organization.
The young leave the cocoon as fully formed earthworms in which, however, the genitalia are not fully developed.
Sporosac springing from m, a modified hydriform person (blastostyle): the genitalia are seen surrounding the spadix or manubrium.
The genitalia in any male fetus is ambiguous.
The Nematomorpha form an isolated group; at first sight they seem to be connected with the Nematoda, but in reality their only common feature is the tubular genitalia opening into a cloaca, and it seems at present impossible to connect them with the Annelida.