44 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Ascons” The author recognises three genera : — Clcitlirina with nine spe- 
cies, Leucosolenia with four species, and Ascandra with one. There re- 
main many other known species of Ascons to which this classification 
must be fitted if it is to be rendered complete. The relations of the 
genera are indicated by the genealogical tree which we reproduce 
below : — 
Calcareous Sponges from Ternate.* — Herr L. Breitfuss has a pre 
liminary communication on the calcareous sponges collected at Ternate 
by Prof. Kukenthal. The material is said to have been well preserved, 
and the ten examples collected belong to six species and five genera, 
none of which appear to be new. 
New Calcareous Sponge.f — Herr L. Breitfuss has a short prelimi- 
nary contribution on the new heteroccelous calcareous sponge which he 
calls Amphoriscus semoni. It has the form of a delicate silvery cylin- 
drical tube, attached by means of a thin curved stalk to the shell of 
Avicula. Though found at Amboina, it calls to mind two Adriatic spe- 
cies, from which, however, it is to be distinguished by the character of 
its spicules. 
Protozoa. 
Nucleus of Protozoa.J — Miss M. Greenwood has published the first 
part of a study on structural changes in the resting nuclei of Protozoa. 
Sbe now treats of the macronucleus of Carchesium polypinnm. This 
creature was selected on account of the size and distinctness of its nuclear 
constituents, and from the fact that long use has made the author familiar 
with the structure and habits of the animal. This macronucleus has a 
strong affinity for stains, and consists in its maturity of four structural 
elements : — (1) The protomacrosomes, (2) the protomicrosomes, (3) the 
nucleochyme, and (4) the nuclear membrane. The first of these con- 
stituents are complex mobile bodies, especially prominent in the majority 
of stained specimens. Their complex character and action are suggested 
by, firstly, their reaction with dyes ; for, staining selectively with eosin, 
they may also colour deeply with methylen blue. In the second place, 
* Zool. Anzeig., xix. (1S9G) pp. 433-5. f Tom. cit., pp. 435-6. 
% Journ. of Physiol., xx. (18J6) pp. 427-54 (l pi.). 
