8 - pong , 1 
SPONGIiE. 
BY 
E. A. Minchin, B.A. 
INTRODUCTION. 
The amount of Sponge literature for this year is not very large, but 
contains some valuable additions to our knowledge of this group . Fore- 
most amongst them may be mentioned the works of Maas on the 
development of Spongilla, and Topsent (6),* on the structure, system, 
and biology of the Clionidce and Renierince. Other papers of importance 
are : for anatomy and morphology, Dendy (2), on Sollas’s membrane and 
the phylogeny of the Keratosa , and Fol, on the oft-discussed “ filaments ” 
of Hircinia; for embryology, Yosmaer (1), on the development of a 
Silicosponge, and Dendy (3), on the pseudogastrula stage of a Sycon ; 
while the statements of Yves Delage as to the structure of the larva 
of Esperella are very remarkable. Works of systematic importance are : 
Dendy (1), von Lendenfeld (10), PoSta, Topsent (1, 2, 6), and 
Weber. 
Maas shows that the larva of Spongilla does not throw off its 
ectoderm, as supposed by GOtte, but that its ectoderm passes continu- 
ously into that of the adult, while Yosmaer makes the same observation 
on the larva of Myxilla sp. Other interesting points which may be noted 
in the development of Spongilla are : the morula stage ; the curiously 
modified gastrulation ; the closure of the blastopore ; the free swimming 
larva, with all the structure of the adult Sponge, but without openings, 
the formation of which in a mechanical manner constitutes the metamor- 
phosis ; the fixation by the pole of the blastopore ; and the derivation of 
the excurrent system and the chambers from the archenteron, while the 
inhalent system is derived from the ectoderm. 
* This work was published in 1888, but the volume of the Arch. Z. expdr. in 
which it appeared did not reach English libraries until 1890, and the Zoological 
Record of 1888 contained merely the bare name of the paper, the Recorder not 
having been able to see it. Hence I have included it in this year. — E. AJ M. 
