694 SUMMARY OF CURRENT RESEARCHES RELATING TO 
set of fibres is seen running from tbe centre of the arcboplasm to the 
polar ends of tbe chromosomes. The structure of the spindle corre- 
sponds exactly with that of the spermatocyte of Salamandra maculata , as 
described by Hermann, save for the persistence of the nuclear wall in 
Noctiluca , and the consequent modifications. There are also “ Verbind- 
ungsfaden ” wdiich originate from the linin-substance, while the central 
spindle-fibres arise from the archoplasm, and the radial fibres, probably, 
from both the cyto- and nucleo-plasms. 
In the spore-buds the archoplasm lies close to the nucleus up to the 
time of the full development of the spore, just before its detachment 
from the mother animal, and part of it becomes transformed into the 
flagellum, in the same way as Strassburger has shown to happen for 
many vegetable swarm-spores. A centrosome, often of dumb-bell form, 
is generally seen in the centre of the archoplasm ; sometimes there are 
two, and in many cases there are a number of small bodies which stain 
exactly like centrosomes, and may represent what Heidenhain has 
called the group of centrosomes. Neither the origin nor the fate of the 
centrosome is known ; in a few cases it appears to be formed from the 
nucleus. 
Classification of Amoebae.* — Prof. A. Celli and Dr. R. Fiocca 
suggest several points as characters useful for a rational classification 
of Amoebae. (1) Locality ; beginning in the earth they pass into water, 
or into the intestine, but they have not been found in the air-passages, 
mouth or ear. (2) Form, movement, size, and structure are always very 
important, but do not suffice for exact definition. (3) Reproduction is 
always effected by division without previous conjugation, but the rapidity 
with which fission stages succeed one another differs in different species. 
(4) Though the characters of the resting stage are not of much import- 
ance they are not to be neglected. (5) On the other hand the marks 
of the cyst-stage are of great importance, and to a practised eye con- 
clusive. (6) The differences in the length of the developmental cycle 
have a high diagnostic value. 
The authors describe Amoeba lobosa with its four varieties, A. spinosa 
sp. n., A. diaphava sp. n., A. vermicularis , A. reticularis sp. n., and 
A. arborescens sp. n. ; a table is given in which the chief diagnostic 
characters can be easily seen. 
The Life of Amcebse.f — The same authors give a general account of 
the life of Amoebae, with particular reference to their pathological im- 
portance. They found that if the temperature was raised gradually the 
Amoebae might survive 67° ; and further experiments were made as to 
the influence of light, drought, &c. Amoebae have a slight power of 
resisting acids, but a strong power of resisting alkaline reagents. 
Life-History of Foraminifera.J — An abstract is published of Mr. J. 
J. Lister’s observations on the now well-known phenomenon of dimor- 
phism in Foraminifera. Many species are found to be dimorphic, the 
differences lying in the size of the central chamber, the shape and mode 
of growth of the chambers succeeding the megalosphere and microsphere, 
* Centralbl. f. Bakteriol. u. Parasitenk., xvi. (1894) pp. 329-39. 
f Riforma Medica, No. 08, 1894, p. 8, and No. 1S7, p. 20. 
t Proc. Roy. Soc. Lond., lvi. (1894) pp. 155-00. 
