ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
547 
in two, heptamerous in two, octamerous in three ; one had two directive 
pairs separated only by one septal pair of the first order ; five had three ; 
one had four. Other cases arc discussed. The absence of directive 
mesenteries must not be used in establishing groups ; the tendency to 
increase or decrease the number is in most cases at least a purely indi- 
vidual feature. 
Porifera. 
Classification of Rossellidae.* * * § — Prof. J. Ijima discusses this family, 
which he divides into four sub-families, defined in relation to the cha- 
racters of the parenchymal microscleres, and, as far as possible, of tho 
megascleric elements as well. These sub-families are Leucopsacinae, 
Lanuginellinm, Rossellinae, and Acanthascinae. 
Calcareous Sponges from ChilLf — Herr L. L. Breitfuss has studied 
Plate’s collection, and finds ten species, of which five are new, one species 
of Leucosolenia, one of Sycon. and three of Leuconia, — a result which 
may be contrasted with what was known when Haeckel published bis 
‘ Kalkschwamme ’ (1872), in which only three cosmopolitan species were 
recorded from the Chilian region. 
Protozoa. 
Spore-Formation in Amoeba villosa4 — Mr. J. C. Smith observed 
the emergence of spherical masses from an encysted Amoeba , which 
collapsed thereafter. After the ejection, the membranous coverings of 
the units were ruptured and the contained nucleus-like bodies were 
freed. The connection of these with the parent nucleus was not dis- 
covered, but the observation is a very useful one, since reports as to 
spore-formation in Amoebae are few. 
Adriatic Foraminifera.§ — Sig. A. Silvestri gives an account of 
over 150 Adriatic Foraminifera. The three most; abundant species are 
Planorbulina mediterranensis , Pulvinulina vermiculata , and Polystomella 
macella. Among the most interesting Adriatic forms are the following : 
— Vertebralina striata , Peneroplis pertusus var. cristata , Cyclammina 
cancellata, Nodosaria papUlosa, N. obliquata i Sagrina columellaris , and 
Truncatulina tenera. 
Fertilisation-Processes in Rhizopods.|| — Herr L. Rhumbler has 
sought to trace back the fertilisation-process in Metazoa to a beginning 
in Rhizopods. The first step is found in cytotropism, in which chemo- 
tropic substances are secreted between cells. The next step is plasto- 
gamy ; the two apposed naked cells fuse. Selection would favour those 
cells which effected the most advantageous exchanges of material with 
other cells. Plastogamy would be most advantageous shortly before or 
shortly after nuclear division. Gradually cytogamy led on to karyo- 
gamy, which has also its degrees of specialisation. Reduction-bodies 
and polar-bodies may be interpreted primarily as due to the exhausted 
(kriippelhaft) divisions of cells which require karyogamy, but they 
* Annot. Zool. Japon., ii. (1898) pp. 41-55. 
T Fauna Chilensis, Heft ii., Zool. Jahrb , Supplement iv. (1898) pp. 455-70 (1 pi). 
X Trans. Amer. Micr. Soc., xix. (1897) pp. 69-73. 
§ Atti e Rend. Accad. Zelanti, viii. (1896-7), published 1898, pp. 1-114. 
|| Biol. Centralbl., xviii. (1898) pp. 21-6, 33-8, 69-86, 113-30 (14 figs.). 
1898 2 P 
