152 A MONOGRAPH OF THE AUSTRALIAN SPONGES, 



Keller (159) published a very interesting account of the early 

 stages of Chalinula fertilis, which appears to differ slightly from 

 the corresponding stages described by Schulze of other. 



Ganin (160) also augmented our knowledge on this subject. 



Marshall (161) published a detailed description of the develop- 

 ment of species of Reniera. His observations differ from the 

 statements of F. E. Schultze and Barrois (I.e.) The larvae of 

 Reniera filigrana does not pass a Gastrula stage, and does not 

 show the apparent anomaly of having the transparent cells inside 

 and the others outside, as Schultze observed in Sycandra. 



Physiology. 



No branch of our science has been so sorely neglected as this 

 one, and to this it should mainly be ascribed that our knowledge 

 of the sponges appears so theoretical. Most of the statements 

 concerning their physiology are deducted from our experience and 

 knowledge of the functions of cells and organs of higher animals, 

 which are similar to those of the sponges. 



Metschnikoff (162) and myself (163) have made physiological 

 experiments on the digestion of sponges. I (I.e.) have published 

 some facts on the formation of the slime which sponges produce, 

 and on the sensitiveness of the ectodermal epithelium, and have 

 tried to find out the functions of all the different forms of cells we 

 meet with in the sponges. 



Schultze (164) discovered the cells which produce the hornfibres. 



(159). C. Keller. Studien ilber die Organisation und Entwickelung der 

 Chalineen. Z.f.w.Z. Band, XXXIII. Seite, 329. 



(160). Ganin. Zur Entwickelung von Spongilla fluviatilis. Z.A. Band I. 



(161). W. Marshall. Die Ontogenie von Reniera Jiligiana. 7i.i.\, T -7i„ 

 Band, XXXVII., Seite, 321. 



(162.) E. Metschnikoff. Spongiologische Studien. Z.f.w.Z. Band, XXII., 

 Seite, 371. 



(163.) R. von Leudenfeld. Ccelenteraten der Siiisee Neue Aplgsinidce. 

 Z.f.w.Z. Band, XXXVIII. , Seite. 234. 



(164.) F. E. Schultze. Uebcr den Bait und die Entwich lung der Spongien. 

 Die FamUie der Spongidce. Z.f.w.Z. Band, XXXII., Seite, 593. 



