ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
577 
Protozoa. 
Plastogamy of Actinosphaerium.*— Mr. H. P. Johnson lias some 
notes on this phenomenon, which is characterized by non-fusion of 
nuclei. As it is a simpler process than karyogamy it may well be 
regarded as the precursor of nuclear fecundation. The author’s observa- 
tions on A. Eichhorni do not differ materially from those of his prede- 
cessors. The process is not followed by encystment or any notable 
reproductive activity ; but each instance of fusion is very likely to be 
followed by division and considerable increase in number within a day 
or two. It was interesting to observe that the possibility of plastogamy 
sometimes determined whether a colony should survive. As a result of 
continued division the Actinosphseria became so small that they could 
not capture their only food — Bosmina ; the only escape from starvation 
was coalescence. 
Pliocene Foraminifera. j — Sig. G. A. De Amicis gives an outline of 
a forthcoming memoir in which he will describe a deposit of Forami- 
nifera at Bonfornello in Sicily. The deposit is of lower Pliocene age, 
and has been formed in a sea of considerable but not very great depth. 
It included representatives of 9 families, 40 genera, and about 163 
species and varieties. Globigerinidae predominated. 
Nuclear Division in Euglena. J — Prof. F. Blochmann and Herr 
Keuten have found a remarkable type of mitosis in Euglena. The 
resting nucleus shows a central body, the so-called nucleolus, surrounded 
by a mass of minute rod-like bodies, probably bound together by linin- 
tlireads. As division begins, the nucleus increases in size, the rod-like 
bodies become longer curved threads, the “ nucleolus ” elongates into a 
rod, and the chromosomes are grouped in an equatorial plate. This 
divides, as the “ nucleolus ” elongates, into two daughter-plates ; and the 
whole nucleus acquires a dumb-bell shape. The nuclear membrane 
still persists. A median constriction separates the halves. The process 
is most like what Lauterborn has described in Diatomacese, the “ central 
spindle ” there observed (arising, however, outside the nucleus) having 
some resemblance to the nucleolar axial rod in Euglena. 
Gregarine of Lumbricus herculeus.§ — Mr. W. C. Bosanquet has 
had the opportunity of studying the Gregarine of the earthworm which 
was first carefully described iby Lieberkiihn. The organism is of a 
pure white colour, quite opaque, and generally spherical in form ; 
mature examples were found to be plentiful in autumn and winter, con- 
jugation occurred about spring, and in summer only cysts and spores 
could be seen. Granules of paraglycogen were detected in teased 
specimens ; some of the protoplasm was arranged as a continuous capsule, 
and it is possible that it is an arrangement which is preliminary to 
spore-formation ; spores of two sizes were observed. 
Coccidium in Cattle. || — Prof. A. Guillebeau finds that the disease 
known as rothe Buhr in cattle is associated with the presence of Coccidium 
* Journ. Morphol., ix. (1894) pp. 269-76 (4 figs.), 
t Atti Soc. Tosc. Sci. Nat., ix. (1894) pp. 117-9. 
t Biol. Centralbl., xiv. (1894) pp. 194-7 (9 figs.). 
§ Quart. Journ. Micr. Sci., xxxvi. (1894) pp. 421-33 (1 pi.). 
|1 MT. Nat. Ges. Bern, 1893, pp. 8-14 (1 fig.). 
