BY R. VON LENDENFELD, PH.D. 329 



V. The Systematic Position of the Sponges. 



The Sponges are, as I have had occasion to mention above, like 

 all Metazoa, colonies of single cells or roughly speaking, Protozoa. 

 They are very low animals, and so the similarity of them with a 

 congregation of Protozoa is greater than that of higher Metazoa. 



There has existed since.1867, when Leukart placed the Sponges 

 under the Ccelenterata, a dispute, whether the Sponges are 

 Metazoons or Protozoons. The greatest authorities on the subject 

 consider them as Coelanterata (Leukart, Haeckel, Claus, F. E. 

 Schulze, Marshall, Vosmaer, Ray Lankaster), whilst others, 

 particularly the majority of English authors, who in otio cum 

 dignitate, do not take much notice of what anyone else does (O. 

 Schmidt, Vorwort zu den Spongien des Meerbusens von Mexico), 

 and the Americans consider it ridiculous to call the Sponges 

 Ccelenterata, but persistently call them colonies of Protozoa. 



To me this dispute seems very useless, and in fact ridiculous. 

 Of course the Sponges are colonies of Protozoa, but so are the 

 Medusae and corals ; of course the sexual propagation is initiated 

 by conjugation — but so it is in the Medusae and corals. Of 

 course the Sponges consist of a zoaglealike ground substance in 

 which cells are imbedded and which is surrounded by Epithelia — 

 but so do the Medusae and corals. 



There are of course great differences between Medusae and 

 Sponges — but are there not as great difference between a parasitic 

 cirrhiped and a lobster 1 Among the essays on this subject which 

 have been published recently, there is particularly one which I 

 shall translate here, because it points out the matter so clearly and 

 simply. (Marshall, Die Ontogenesis von Reniera filigrana. Zeit. 

 schrift fur wissenschaftliche Zoologie Band, XXXVII. Seite, 

 239-216. 



It is known (but it does no harm to point to it from time to 

 time) that Leukart (1) drew attention to the fact that the Porifera 

 belonged to the Ccelenterata in the first instance. This was in his 

 review of Lieberkuhn's Essays on the Anatomy of the Calci- 

 spongi . 



(1.) Jatresberichte, 1SG4-65, p. 196 and 197. 



