70 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
for a considerable time in ice. Observations on tbe development of 
deformed sponges show that larvae for the most part bereft of their 
ectoderm may grow into young sponges. 
Revision of Hyalonematidge.* — Prof. F. E. Schulze discusses this 
interesting family, contrasting the genera, and giving diagnoses and 
tabular keys of the species, 6 of PJieronema , 2 of Poliopogon, 20 of 
Hyalonema, and Semperella ScTiultzei. He expresses his conclusion as to 
the phylogenetic relations of the genera in this scheme. 
that portions deprived of the central capsule are able to again become 
complete spheres, and for some time to exhibit normal formation of 
pseudopodia, until they die down under the influence of certain 
degeneration-phenomena. Parts without a capsule may be saved by the 
introduction of a central capsule, even though it be that of another 
individual, and isolated central capsules are able to become regenerated 
into complete individuals by the fresh formation of pseudopodia, 
gelatinous envelopes, vacuolar layer and pigment. Isolated non- 
nucleated capsular contents may, under suitable conditions, live for a 
time, and exhibit normal formation of pseudopodia, and central capsules 
which have not been much injured, but whose nucleus is extirpated, may 
live still longer ; during this period they regenerate a layer of pseudo- 
podia, secrete a definite quantity of gelatinous substance, and begin to 
form vacuoles. Isolated nuclei, in all cases, die after a more or less 
short period, without exhibiting any regeneration-phenomena. 
The author’s views as to the importance of the nucleus may be 
judged from his statement that the physiological significance of the 
cell-nucleus depends on its metabolic relations to the rest of the cell- 
body. It is only by these that it possesses any influence on the function 
of the cell. 
A New Heliozoon.J — Prof. C. Sassaki describes a small marine 
Heliozoon, which he names Gymnospliseria albida g. et sp. n. In the 
* SB. Akad. Preuss. d. Wiss., 1893, pp. 541-89. 
t Arch. f. Ges. Physiol., li. (.1892) pp. 1-118 (6 pis.). See Bot. Centralbl., lv., 
(1893) pp. 332-4. 
X Jenaische Zeitschr. f. Naturvviss., xxviii. (1893) pp. 45-52 (1 pi.). 
