EMBRYOLOGY, PHYSIOLOGY, ETO., DISTRIBUTION. SpOtlg. T 
NOldeke (35) describes the metamorphosis of Sponglllidce. According 
to him, they form a typical gastrula, but the epiblasfc degenerates after 
the larva has become fixed, and takes no part in the future development. 
Thus the Sponges have nothing in Common with other Metazoa in the 
developmental stages beyond the gastrula. 
Perez (36) has a short paper on the homology of the germinal layers 
of Sponges, criticizing the views of Delage, Barrois, and others. 
Wilson (52, 53) gives a detailed account of the gemmale and egg 
development of Marine Sponges, agreeing essentially with his preliminary 
notice on the same subject, published three years ago. [See Zool. Rec. 
1891, Spongice , p. 18, where a long abstract is given.] He describes the 
adult structure and gemmule development of Esperella fibresilis , n. sp., 
and of Tedania brucei , n. sp , the adult structure and egg development of 
Tedania fcetida , n. g. & sp., the early stages in the egg development of 
Hircinia acuta , and concludes by makiug some general remarks on the 
morphology of Sponges and their gemmule development. 
c. Physiology. 
Von Lendenfeld (24) offers some critical remarks on the nutrition of 
Oscarella. 
Letellier (28, 29) attempts to explain the boring action of Cliona as 
a purely mechanical process, viz., as a pulling action on the part of the 
contractile cells of the Sponge, which removes minute particles of the 
nacreous layer. Topsent (44) states his objections to this hypothesis. 
Masterman (31) has studied the nutritive aud excretory processes of 
Porifera , especially of Grantia compressa. He finds that the choanocytes, 
after having taken up the food particles, are transformed into amoeboid 
cells, and migrate as such into the interior of the Sponge, where intra- 
cellular digestion takes place. Solid food particles are excreted by 
amoeboid cells which burst through the ectoderm. The strong resem- 
blance between these and the corresponding processes in Choanojlagcllula 
are pointed out. 
b. Methods of Preservation. 
Pintner (38) recommends Formol for the preservation of Sponges. 
III.— DISTRIBUTION. 
a. Faunistic. 
For the general distribution of Spongillidoi see Hanitsch (10), and 
especially Weltner (51). 
St. Thom4 : Moller (34). 
Europe, generally : Spongillidce ; Petr (37). 
Ireland, East Coast: Duerden (9 Spongillidce, with 2 or 3 
American species ; Hanitsch (15, 16). 
