52 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
clear space which does not appear to he a vacuole. The author recom- 
mends the close study of these constituents of amoeban organization. 
The other granules are distinguished as the elementary, since they are 
believed to be proper elements of the protoplasm ; they are considerably 
larger than the “ glanzgranula,” very feebly refractive, extremely pale, 
and only to he detected during life by means of good immersion-lenses. 
Staining experiments show that these granules have a striking resem- 
blance to a cell in petto. 
The author has given considerable attention to the phenomena 
exhibited by the contractile vesicle, which, in the terrestrial Amoebae, is 
of very large size ; he comes to the conclusion that the fluid is not 
driven out of the body, but into it, and he, therefore, regards this vesicle 
not as an excretory apparatus, hut as one that is, in the first place, cir- 
culatory and respiratory. The vesicle, as it collects the fluid in the 
endoplasm, comes near to the surface of the cell, where an exchange of 
gases can be effected. The fresli oxygen is driven through the body on 
the contraction of the vesicle. The passage of the fluid through the cell 
serves also to prevent the drying up of the protoplasm. 
In conclusion, Prof. Greef gives a revision of the terrestrial Amoebae, 
of which he recognizes five species; three of these are uninuclear; they 
are A. terricola Gr., A. similis sp. n., A. sphseronucleosus, with which 
he associates his formerly described A. granifera and A. gracilis ; this 
last is generally much smaller than the others. The two multinuclear 
species are both new, and are called A. fibrillosa and A. alba; the 
small forms of the former have twenty to fifty nuclei, and the larger 
one hundred and more. In the latter species the nuclei are also very 
numerous, but they are larger than in A. fibrillosa, and always have ten 
or twenty nncleoli. 
The Animal-like Nutrition of some Peridinidse.* — Herr A. J. 
Schilling describes how one of the naked fresh-water forms — Gymno- 
dinium hyalinum sp. n. — feeds upon Chlamydomonads. It loses its cilia 
and gives off amoeboid processes, which engulf the monads. This 
discovery corroborates what has been observed in regard to Gymnodinium 
roseolum (Sclimarda), G. Vorticeilla (Stein), G. spirale and G. gracile 
(Bergh), and Polylcritos auricularia. All these are naked forms. But 
Schilling has also discovered the same mode of nutrition in Glenodinium 
edax sp. n., which is one of the encapsuled types. It seems, therefore, 
definitely settled that the members of this family, which are without 
chromatophores, do feed after the fashion of animals. 
A new Form of Trichonymphidse.f — Prof. J. Frenzel describes 
Leidyonella cordubensis g. et sp. n., a representative of the parasitic 
Trichonymphid*. It occurs in the hind-gut of Eutermes inquilinus (?), 
in Argentina. A colourless oval organism, from 0'2 — O' 45 mm. in 
length, it is contractile and active, especially in its anterior region, 
which is conically pointed and bears a tuft of undulating cilia 
almost as long as the whole organism. The cuticle exhibits oblique 
longitudinal ridges which are continued into a twisted caudal tuft. 
There is a simple round nucleus, but no micronucleus, nor contractile 
* Ber. Deutsch. Bot. Gesell., ix. (1891) pp. 199-208 (1 pi.). 
f Arch. f. Mikr. Anat., xxxviii. (1891) pp. 301-16 (4 figs.). 
