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SPONGIIDA. 503
MIKLUCHO-MACLAY (Mem. P^tersb. 1870) considers the pores and
oscula of sponges homotypic structures, and that the osculum may originate
by the union of pores or by the development of a pore. If this be the case,
then, as Oscar Schmidt remarks (op. cit. p. 84), the whole ccelenterate theory
falls to the ground, as the mouths and cutaneous pores of ccelenterate polypes,
with which the oscula and pores of sponges have been compared, are certainly
not homotypic or homologous structures. But Schmidt does no.t think
that Maclay's theory is borne out by the simplest sponges, though in Geodinae
in some cases pores may enlarge to pseudoscula.
CARTER (Ann. N. H. (4) vi. pp. 329-341) notices in marine sponges
(Haliehondria simulans, Johnston, and Grantia nivea) the tessellated aggregations
of sponge-cells which he previously described in SpongUla as
" ampullaceous sac," and which he considers to be the special digestive
organs of the sponge. Carter thinks that the sponges, as possessing distinct
channels for excretory purposes, are more akin to the Polyzoa and Tunicata
than to the Corals, and compares also the canaliferous structure of the
ccenosarc of compound Tunicata to the canal-system of sponges (ib. p. 336).
Regarding the question of sexual generation in the sponges, Carter likewise
mentions certain uniciliated bodies in Microeiona atrosanguinea, which he
considers may possibly be spermatozoa, and certain minute spherical cells or
capsules in Haliehondria panicea, possibly true sexual ova (ib. pp. 339-341).
LIEBERKUHN (Ann. N. II. (4) vi. p. 497) maintains that the contractile
substance of SpongUla consists of independent nucleated cells, separable
by heating the sponge to a temperature of about 140° F., and that in certain
cases, as in the formation of the siliceous parts of the gemmules, the spongecells
may reproduce the plan of the vegetable cell. [The Recorder has not
had an opportunity of seeing the original paper on the " Motory Phenomena
of Animal Cells," in Schriften Ges. Marburg, ix. J
VAILLANT (I. c.) describes two sorts of papillae in Cliona celata ; the first
with large openings, the second more numerous, with small openings, misunderstood
by Grant, who supposed they were a transitory state of the large
ones. According to Vaillant the large ones are oscula, the small are pores or
inhalant openings.
CARTER (Ann. N. H. (4) v. pp. 73-83), after comparing Grayella cyathophora,
Carter, and Osculina polystomella, 0. Sdt., with Cliona northumbrica,
Hancock, comes to the conclusion that the two former are free forms of
the Clionidae. Raphyrus yriffithsi, Bbk. (given by Schmidt as a synonym of
his Papillina suberea), he considers to be but a free form of Cliona celata,
Lbk. He considers (ib. p. 82) the question decided that certain sponges may
feed on the organic matter of shell-substance, just as certain fungi feed on
woody tissue.
OSCAR SCHMIDT (Spong. Atlant. p. 13) proposes the term Hexactinellida for
the siliceous sponges with sexradiate spicules ( Vitrea, Wyville Thomson). In
a second new family, Lithistida, the same author includes his new genera
Leiodermatium and Corallistes. They have a continuous siliceous skeleton ;
but its fibres or spicules do not belong to the sexradiate type, but form an
apparently quite irregular confused network.
The same author (op. cit.) divides the sponges into four great divisions or
orders, to which, however, he does not as yet give definite names:—
I. Spicules of sexradiate type:—Hexactinellida and (extinct) Ventriculitida.