PREVIOUS INTERPRETATIONS OF CNIDARIA 167 



found in Scyphozoa, and this lead Goette to unite the two 

 classes into one taxon of Scyphozoa. There were some zoo- 

 logists who were opposed to such a classification. I finally 

 succeeded in showing (Had^i, 1907) that there is no ectodermal 

 gullet in scyphopolyps, neither is there one in Scyphomedu- 

 sae (Heric, 1907), and this has now been generally accepted. 

 It seems that in the Anthozoa both a functional as well as 

 genetic correlation had been developed between the formation 

 of sarcosepta and the formation of the gullet so that they are 

 simultaneously subject to a progressive reduction when the 

 retrogression starts. We must atribute to the formation of 

 retractors in the taeniolae the fact that we can neverthless find 

 remainder of earlier richly developed septal apparatus in the 

 scyphopolyps. The formation of a gullet is extremely charac- 

 teristic of Turbellaria. Organs with a very complicated 

 structure have been developed in several directions from a 

 simple invagination of the skin around the oral opening 

 (pharynx simplex). Special names have been given to these or- 

 gans. The pharynx became protractile due to the formation of 

 circular folds so that finally it developed into an important 

 organ by means of which animals that adopted the vagile 

 and predatory way of life were able to catch their prey. This 

 gullet has been called an 'E.rgreiftmgsorgan (organ of gripping) 

 by Ludwig Graff de Pancsova, who came from the region 

 of present day Yugoslavia, formerly the leading expert in 

 Turbellaria (v. Graff, 1878: 199). This organ has been develop- 

 ed progressively, in the same w^ay as the hermaphroditic 

 copulation organ. It may not be superfluous to mention here 

 that the formation of a pharynx had been adopted by all the 

 numerous descendants from Turbellaria, either in its complex 

 form as a genuine muscular pharynx (e.g. in many classes of 

 Ameria), or in its reduced form as a stomodaeum. We can 

 find the stomodaeum everywhere up to the Chordata. This 

 stomodaeum has been preserved even in those animal types 

 which have entirely adopted the sessile way of life, as in 

 Endoprocta, among Ameria, and in nearly all Oligomeria 

 12* 



