BY DR. R. VON LENDENFELD. 



143 



form a low ciliated Epithelium. The intermediate layer which 

 forms the bulk of the sponge, consists of a soft gelatinous or 

 harder cartilaginous substance, like the gallert of the umbrellas of 

 the Medusae, in which cells of different shapes are embedded. 

 These cells are partly elongate, muscular, partly star shaped 

 tissue cells, partly horn-producing, gland cells, ova, spermatophors, 

 and so on. 



Keller (103) and Metschnikoff (104) agree in the main points 

 with Schulze. 



Schulze (105) describes a new form of propagation of sponges, 

 by floating polycellular buds. 



Sollas (106) made experiments to show the influence of caustic 

 potash on the spicules ; he published a series of anatomical and 

 histological researches, which contain a great many interesting 

 facts, and are worthy of comparison with Schultze's classical works. 



Also, Carter (107) published some data on the structure of 

 sponges, but unfortunately without noticing the previous publica- 

 tions on the subject. 



Schulze (108) published in 1881, a paper on the soft parts of 

 Euplectella, from which we learn, that the Histology of this well- 

 known sponge, corresponds with the minute structure of sponges 

 belonging to other groups. 



(103). O. Keller. Untersuchung ilber die Anatomle und Entioichelungs- 

 geschichte einiger Spongien des Mittelmeeres. Basel, 1S76. Ueber den Ban von 

 Meniera semitubulosa. Z. f. w.Z., XXX., Seite,563. Studien ilber Organisation 

 und Entwiclctlung der Chalineen. Z. f. w. Z., XXXIII., 317. Neue Coelen- 

 enteraten aus dem Golfe von Neapel. Arch. f. mik. Anat. XVIII., 271. 



(104,). E. Metschnikoff. Beitrdge zur Morphologie der Spongien. Z, f. w. Z. 

 Baud. XXVII., Seite, 275. Spongiologische Studien. Seite, 349. 



(105). F. E. Schulze. Ueber die Bildung freischwebender, Brutknospen bei 

 einer Spongie Halisarca lobularis. Zool. Anz. II., Seite, 636. 



(106). Sollas, Sp>onge fauna of Norway. Ann. Mag (Series 5), Vol. V., 

 p. 130. Vol. V., p. 241. Vol. V., p. 396. Vol. IX., p. 141. Vol. IX., p. 426. 



(107). H. Carter. Contributions to our knowledge of the Spoibjida II., 

 Ceratina Ann Mag., Vol. VIII., p. 101. On the development of the fibre 

 in the Sx>ongida. Ann. Mag., Vol. VIII., p. 112. 



(108). F. E. Schulze. Of the soft parts of Enplectella aspery ilium. Trans. 

 Roy. S., Edinburgh., XXIX., p. 636. 



