314 THE EVOLUTION OF THE METAZOA 



Is the Plasmodial State of the Acoela 

 a Primary Element? 



The antagonists of the new interpretation soon discovered 

 its critical point; they beHeved that at this point they had 

 the best chance to attack my concept. This point is the primary 

 nature of the plasmodial state that can be found in the Acoela 

 and in other Turbellaria. This was followed by a cellularization. 



Erich Reisinger, endeavours to prove the faults of my 

 thesis of the primary plasmodial state of the primitive Metazoa, 

 the Turbellaria included. He believes that in a pplykaryonic state 

 we must always see secondarily developed syncytia. He tries to 

 support his criticism not only by means of facts that he collected 

 in some occasional observations, but also with experiments. 



In order to make his interpretation of proposed facts all 

 the more acceptable Reisinger initially makes an unproved 

 statement in which he declares our concept to be "schon auf 

 Grund der total verschiedenen Sexualverhaltnisse der gamo- 

 togamen CiUate einerseits und der gametogamen Metazoen 

 andererseits als ausserst problematisch erwdesen." 



Let us now consider those facts that were used by Reisinger 

 as a basis of his conclusions, and above all the proof he 

 obtained by way of an experiment. Reisinger pressed through 

 a silk -gauze an already cellularized freshwater triclad Planaria 

 polychroa O. Schmidt. In the separated rags of tissue Reisinger 

 could see spheric complexes (the so-called ''Spharien") being 

 developed in spots where cells ran together to form syncytia 

 (with the exception of a few cells that remained amoeboid). 

 Many parts became histoHzed. Thus syncytia similar to the 

 central parenchyma (= endocyte, according to Westblad) of 

 the Acoela (all the syncytia are actually similar!) have been 

 developed from the cellular tissues. 



Observations have shown that under the influence of the 

 protozoic parasites (Sporozoa) of the species Emoccidium 

 monoti the cellular intestine of the species Otomesostoma can 

 change back into a syncytial state. Such a development can 



