PREVIOUS INTERPRETATIONS OF CNIDARIA 105 



yet we always find that pure anthopolyps emerge as a result 

 of such a development. 



We come now to the phenomenon of transfission which 

 the Cnidaria, and above all the Anthozoa, have inherited, in our 

 opinion, from their turbellarian ancestors. The conditions in 

 Gonactinia, a solitary animal that possess no skeleton, are very 

 simple and resemble to a surprising degree those that can be 

 observed in several rhabdocoelous Turbellaria. One species 

 among the Madreporaria that is most prone to form cormi, has 

 excited a great interest of zoologists. This is Fungia. In it the 

 alternation of generations connected with transfission has been 

 introduced, in spite of its well developed and comparatively 

 heavy calcareous skeleton (Fig. 28 p. 155). It closely resembles 

 the alternation of generations that can be observed in Hydrozoa 

 and in Scyphozoa, particularly in Scyphozoa, because of the 

 unequal transfission (which is close to the axial budding). The 

 distal half of the maternal animal becomes considerably broa- 

 dened and flattened; it liberates itself and, though completely 

 passive, it is caught up by the water current and it settles down 

 with its flattened side on the sea bottom not far from the 

 maternal polyp. This anthopolyp, which is in its form only 

 slightly changed, takes over the sexual function. The maternal 

 polyp by way of an unequal transfission produces another 

 sexual polyp, which is again separated from its maternal body. 



Though we are reminded strongly by this situation of con- 

 ditions that prevail in the metagenetic Hydro- and Scypho-zoa, 

 we find nevertheless that inF////^/^ the sexual generation corre- 

 sponds to that of an anthopolyp, and there is therefore no 

 trace, or no trend, (with the exception of its flattening) to a 

 medusa form. Here we can raise the question: could Fungia 

 perhaps be a very primitive species of Anthozoa so that it 

 could be considered to be the beginning of the formation of 

 medusae which has finally led, in the remotest geological past^ 

 to the metagenetic subtype of Scyphozoa with medusa as their 

 sexual generation? This is completely improbable, and on the 

 contrary, Fungia appears to be a specialist among Madreporaria. 



