496 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
colonial form which he calls Sphseroeca volvox. The colony consists of 
numerous choanoflagellate individuals, and seems to be most nearly 
related to the genus Protospongia. A new species of Bicosceca — B. 
socialis — was found, which differs from all other species in being free- 
swimming instead of fixed. The individuals are loosely attached 
together to form star-shaped colonies, in which each individual is 
furnished with a hyaline investment. The peculiarities of the “ stalk,” 
by means of which the organism is attached to its investment, show that 
this is to be regarded as a modified second flagellum, equivalent to the 
trailing flagellum of the Heteromastigodes. Another very remarkable 
form, to which the name of Thaumatomastix setiferum was given, has its 
surface furnished with numerous scattered bristles. It has also two 
flagella of unequal size, but was observed at times to emit pseudopodia, 
a very remarkable circumstance in a form apparently so highly speci- 
alised. There is no mouth, and the pseudopodia must be used in food- 
catching. The paper includes descriptions of several other new forms. 
Notes on Protozoa.* — Herr S. Prowazek sums up the results of his 
experiments on the intra vitam staining of Protozoa with neutral red. 
He also describes the cyst of a Paramsecium and the emergence of the 
animal, the conjugation of three individuals of Cyclidium glaucoma , the 
alteration in the rate of the contractile vacuole’s pulsations in dividing 
Infusorians, and so on. 
New Peridiniacese from the Atlantic-! — Mr. George Murray and 
Miss Prances Whitting publish specific descriptions of the Peridiniaceae 
collected by the pumping method during various Atlantic journeys. 
The paper is of interest because it is the first attempt which has been 
made to draw up specific diagnoses for the group. The paper includes 
elaborate tables of distribution. 
Development of Fresh-water Peridiniaceae4 — Dr. Y. Folgner has 
been able to make a series of observations on this subject. The first 
material obtained consisted of winter cysts of Ceratium tetraceros. 
These were received in the middle of October, and in a window protected 
from frost the organisms began to leave their cysts in the second half 
of February. The actual rupture of the cysts was not observed, but the 
newly hatched individuals were somewhat egg-shaped structures without 
horns or membranous investment, but with a distinct transverse furrow. 
The protoplasm was dark in colour owing to the compacted chromato- 
phores. Soon after hatching the organisms displayed a slow circular 
movement, the swinging movement being accompanied by amoeboid 
changes of form. In addition to these temporary changes, the body 
shows a gradual but permanent alteration, so that the ovoid shape is 
lost, the anterior and posterior horns grow out, the membrane becomes 
distinct and acquires its sculpturing, and at the end of about six hours 
the animal acquires the characteristics of the “ spring form ” as it occurs 
in natural condition. This form differs from the autumnal one in the 
greater simplicity of the investment, and the entire absence of the third 
horn. The author does not believe that a true seasonal dimorphism exists, 
* Zool. Anzeig., xxii. (1899) pp. 339-45 (1 fig.). 
t Trans. Linn. Soc. (Botany), v. (1899) pp. 321-42 (7 pis.). 
X Oesterr. Bot. Zeitschr., xlix. (1899) pp. 81-9, 136-41, 221-6, 257-61 (1 pi.). 
