78 QUARTERLY CHRONICLE OF MICROSCOPICAL SCIENCE. 
Franz Eilhard Schultze, in ‘ Arch. fiir Mikrosk. Anat.,’ 
vol x, third part, describes “‘ The structure and reproduction 
of Actinospherium Eichornii,’”’ multicellular structure of adult, 
encystation in a jelly, breaking up into ten “ sporules,” 
each of which becomes enclosed in a_ siliceous hexagonal 
shell. The same author, in a paper in the fourth (last pub- 
lished) part of vol. x of the same ‘ Archiv,’ describes and 
figures a new species of Archer’s genus Raphidiophrys, also 
three new genera, one a stalked form, like Clathrulina, but 
devoid of siliceous capsule. 
A supplementary number of the same ‘ Archiv’ (1874), of 
220 pages and five plates, gives an account of studies carried 
out on Heliozoa and Ameceboidea by Dr. Richard Hertwig and 
E. Lesser. ‘The forms described come from the neighbour- 
hood of Bonn. Ina first chapter the authors show that Mr. 
Archer’s Gromia socialis and his Cystophrys Haeckeliana are 
one and the same thing, viz. a colony-forming ameeboid 
rhizopod, which they term Microgromia socialis. A variety 
of new genera and species are subsequently described and 
figured, and classification of the groups given, with frequent 
reference to and discussion of Mr. Archer’s observations. 
Spongie.— Metschnikoff, in Koll.u. Siebold’s Zeitschrift, first 
part, 1874, takes up the development of certain Calcareous 
Sponges, and makes his observations the ground for a severe 
attack upon Haeckel. He studied Sycon ciliatum. It is not 
impossible that the difference of his results with those given 
by Haeckel is due to the difference of species studied. ‘This 
he does not take into consideration. The eggs undergo 
cleavage whilst still attached to the endoderm of the parent 
sponge-cup. Later the embryos escape, and may be ob- 
tained in the glass vessel in which the specimens are kept, by 
placing glass slips conveniently for their adhesion. The ob- 
servations were made in the spring of 1868, at Messina. The 
ciliated swimming embryos are composed of cells surrounding 
a cleavage cavity. The anterior cells only are ciliated 
(as described in other sponges by earlier authors). ‘The 
cleavage cavity disappears, the ciliated cells become in- 
vaginated, losing their cilia, and form the endoderm, 
whilst the large unciliated cells form the  skeleton- 
building layer of the young sponge. The orifice of 
invagination closes, and probably a secondary orifice breaks 
through at a later period, to form the permanent mouth or 
excurrent aperture of the sponge-polyp. In the cases studied 
by Haeckel an invagination is not described, but the diplo- 
blastic planula, without any orifice, is described as forming 
its endoderm by delamination, an orifice (regarded as the 
