206 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
of plates or scales. Verworn is strongly disinclined to believe that 
Difflugia exercises any “choice ” in regard to the particles used in forming 
the extrinsic part of the shell. Thus in the basin whence his specimens 
of D. lobostoma were obtained, there were no sand particles, and conse- 
quently none on the shells. Moreover, he was able to see specimens 
clothing themselves with powdered glass when that was the only 
available material. The character of the shell depends mainly on what 
material can be most conveniently obtained, and on the mechanical 
conditions of architecture. 
In studying the conjugation of Difflugia , unions of three and even 
four were repeatedly observed. The process is characterized by the 
appearance of a small, peculiarly shaped accessory nucleus beside the 
usual one, and during conjugation the small nuclei of two individuals 
come into close relations — facts evidently suggestive of what obtains in 
ciliate Infusorians. By numerous experiments on artificially divided 
specimens, Verworn has convinced himself that the nucleus is not a 
“ psychical centre ” of the cell, that normal movements persist for a time 
in portions without nuclei, and that these eventually cease because of 
molecular disturbances resulting from the absence of the nucleus, which 
has therefore an indirect but not a direct influence on movement. 
Cytophagus Tritonis.* — Under this name Herr J. Steinhaus gives 
an account of a Coccidium which lives parasitically in the cells of the 
enteric epithelium of a Triton. The creature has the form of a small 
rounded cell which incloses a vesicular nucleus with a small nucleolus 
and some small pigment-grains. The diameter of the body varies from 
2 to 9 /x. Proliferation commences with mitotic changes in the nucleus. 
After cell-division the products become sickle-shaped corpuscles, 6 to 7 p 
long ; they become grouped in the cavity caused by the parasite in the 
body of the epithelial cell ; they next take on an amoeboid form, 
and wander from the cells in which they were produced. There is no 
cyst during any part of the period of proliferation. 
In this last point Cytophagus agrees with the Karyophagus Salamandrse 
already described by the author, but the differences between them are 
such as to necessitate the establishment of a new genus for the parasite 
of the Triton. 
Foraminifera collected off the South-west of Ireland.f — Mr. J. 
Wright gives a report on the Foraminifera collected in 1888 by the 
expedition sent out by the Eoyal Irish Academy, and concludes with a 
table of distribution of the 216 species of Foraminifera known from the 
south-west coast of Ireland. 
* Centralbl. f. Bakteriol. u. Parasitenk., ix. (1890 [1]) pp. 50-2. 
f Proc. Koy. Irish Acad., i. (1891) pp. 460-502 (1 pi.). 
