438 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
than in the allied Spirochona, for it is a funnel but without the spiral ; 
there are four peristomial spines to which the generic title refers. 
A definite centrosome is present, quite distinct from the micronucleus, 
It divides only at one pole during nuclear division, whioh suggests that 
it has not directly to do with the latter. After the completion of the 
nuclear spindle, there is one centrosome at one pole, and there are two 
at the other. From the observed stages of nuclear prophases, the division 
appears to be mitotic. 
The stimulus to budding seems to come from the division of the 
nucleus ; no part of the peristome is taken over into the bud, which is 
distinctly nucleated. Budding is most frequent when' the host has cast 
its shell, when a new dwelling has to be found. 
New Infusoria.* — Dr. A. C. Stokes publishes a description of a 
number of Infusoria which he believes to be undescribed. In addition 
to the forms that are undoubtedly Infusoria, the author includes 
descriptions of three species of Trachelomonas. 
Vasicola annulata.j — Dr. A. C. Stokes describes a second species 
of this genus, which differs from the V. ciliata described by Tatem in 
having a brackish water or marine habitat. It is stated that this species 
affords a brilliant example of the production of a membraniform ecto- 
sarc. 
Calcituba polymorpha.J — Dr. F. Schaudinn gives a description of 
the structure and life-history of this Foraminifer. From naked plas- 
modia there arise large, manv-chambered, stellate individuals. The 
plasmodium settles on growing algae, and forms a shell ; from this first 
chamber, dichotomous calcareous tubes grow in a radial direction. 
While the peripheral ends of the tubes grow on, the central part falls 
to pieces, when the algal substratum is destroyed, and fragments includ- 
ing a variable number of chambers sink to the floor. Thus from the 
large, star-shaped individual, a ring of radially disposed smaller indi- 
viduals arises ; the latter form more new chambers at their peripheral 
ends, while the older central parts break up and fall away — a process 
which in some respects resembles strobilation. The fragments may find 
new algse and grow further, or they may encyst, or they may liberate 
plasmodia, which directly, or after a period of independent life, or after 
division, give rise to the stellate individuals. 
The plasm includes clear vacuoles, reserve granules, pigments, ex- 
cretory granules, &c. The matrix shows a webbed vacuolar structure. 
Two plasmic fluids of different consistency and refractive index exhibit 
streaming movements. The shell consists of a chitinous excretion and 
four or five layers of little capsules whose walls are thickly covered with 
refractive granules of carbonate of lime. The making of this shell is 
carefully described. 
The nuclei occur in four stages : — (1) Homogeneous, intensely 
stainable, membraneless nuclei, with great variety of size (2-10 //.). 
(2) Nuclei with a vacuolar (optically reticulate) framework, more 
* Proc. Amer. Phil. Soc., xxxiii. (1894) pp. 338-45 (1 pi.). 
t Journ. New York Micr. Soc., xi. (1895) pp. 47-51 (1 fig.). 
X Zeitschr. f. wiss. Zool., lix. (1895) pp. 191-232 (2 pis.). 
