434 THE DIGESTION OF SPONGES, 



THE DIGESTION OF SPONGES EFFECTED BY 

 ECTODERM OR ENTODERM? 



By R. Von Lendenfeld, Ph.D. 



In my paper on the Australian Aplysinidae (1) I gave an 

 account of the experiments which I had carried on for the purpose 

 of obtaining some information concerning the digestion in Sponges. 

 The main result of these experiments was that the Epithel of the 

 ciliated chambers is not to be considered as an organ of digestion, 

 that all cells of the Sponge freely take up Carmine when in 

 contact with them, and that therefore the cells of the Epithelia of 

 Sponges kept in water containing Carmine were soon found full of 

 ( '.irmine granules, but that the Epithel of the ciliated chambers 

 soon ejects the Carmine again whilst the cells of the upper surface 

 of the subdermal cavity give it off to the amoeboid wandering 

 cells of the Mesoderm, and that these transmit the Carmine 

 granules after they have been partly digested, to the cells of the 

 ciliated chambers for ejection. I concluded from this that the 

 digestive function of the Sponges which I experimented on was 

 centralized in the upper wall of the subdermal cavities, and that 

 in Sponges which do not possess a highly developed cavity of this 

 kind the digestion was effected by the Epithelia of the introductory 

 canal system. 



According to F. E. Schulze (2) the introductory canal system of 

 the Sponges is produced by a complicated folding process of the 



II.) R. von Lendenjeld. Coelcnteraten der Siidsec II., Neue Aplysinidae 

 Zeitschrift fur wiss. Zool. Band XXXVIII.. Seite 262 ff. 



(2.) F. A'. Schulze. Uber den Baa und die Entwickelung der Spongien. 

 Die Plakiniden. Zeitschrift fur wiss. Zool. Band XXXIV., Seite 439. 



