NEW INTERPRETATION OF CNIDARIA 315 



take place, so to speak, normally in Planariae when they take 

 too much food, a fact which is also mentioned by Reisinger. 

 By means of some not too tender experimental interventions 

 Reisinger succedded in leading a syncytial skin layer into a 

 cellularized state (in Gyratrix and in Koinocystis)\ he used strong 

 irritations in this experiment. Reisinger also succeeded in 

 artificially stimulating the opposite process to the one first 

 mentioned. He mentions the fact which he believes to be in 

 itself a firm proof, that in all the ontogenies of the lower 

 Turbellaria that have become known up to now, these onto- 

 genies take place by way of a cellular development only 

 ("rein zellig"), thus by way of cleavages. 



On the basis of all these facts Reisinger comes to the conclu- 

 sion that there are no primary plasmodia in the Turbellaria 

 but rather secondary syncytia which show a constant incli- 

 nation to return under certain conditions into their cellular 

 components. He ends his discussion with the statement, "Die 

 von Steinbock und von Had^i vertretene Ableitung der Meta- 

 zoen von Ciliaten iiber polyenergide plasmodiale Stadien er- 

 scheint durch unsere Befunde weitgehend erschiittert" (Reisin- 

 ger, 1959:641). 



As regards the "totally different sexual conditions" that are 

 supposed to exist between the Infusoria and the Eumetazoa, 

 we have already shown that in this case we cannot really 

 speak of such a total difference. 



We cannot attribute the same conclusive power to the find- 

 ings made by Reisinger as Reisinger himself would like to 

 give them, in spite of the fact that they are very interesting. 

 Reisinger goes even so far in his endeavours to deny the 

 existence of a primary plasmodial state in the Turbellaria, 

 that he calls Steinbock's opinion a "pure fiction" (Reisinger, 

 1959: 642) which is certainly unjust in view of the fact that 

 Steinbock (Steinbock, 1954) too tried to prove his thesis of 

 primary plasmodia in the Acoela (which he calls archhiston) 

 by means of experiments. 



It is unnecessary to discuss whether there are any true 



