194 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
they grow simultaneously at base and apex. Ac. cilhida appears to take 
three months at least to arrive at the adult stage. 
M. Penard’s independent observations on the pseudopoclia appear to 
confirm Hertwig and Lesser’s description of a Heliozoon as “ rolling after 
the fashion of a ball, and by the contraction of the pseudopodia.” 
The food of the Heliozoa appears to vary with the medium in which 
they find themselves, but they prefer an animal to a vegetable diet. An 
interesting new form, of small size (15 /x) and reddish tint, is briefly 
described ; the ectosarc, a thin light band, is traversed by a line of very 
small tangential spicules, but none radial in direction ; the pseudopodia 
are hyaline, excessively long, and not numerous ; it is by their means 
that the animal runs like a spider, leaping to one side or straight 
forwards with surprising agility, so that it progresses almost as rapidly 
as a Flagellate. It is a true Heliozoon, which resembles some Amoehse 
in the plasticity of its body, and in the character and small number of 
its pseudopodia. A new form of true Monad is also described as having 
filiform rigid pseudopodia similar to those of Acanthocystids, by means 
of which the animal attaches itself to the ground and moves slowly ; it 
can feed equally by the whole of its surface, and is, on the whole, a 
Flagellate with some well-marked Heliozoic characters. 
Anatomical Peculiarity of a Vampyrella.* — Herr W. Wahrlich 
describes a peculiar anatomical structure in a Vampyrella, which he 
believes to be unique. In its amoeba-condition the Vampyrella is indis- 
tinguishable from V. vorax Cnk., but in the encysted condition presents 
the remarkable peculiarity of the digestive vacuole being surrounded by 
a cellulose-membrane. When it has fully passed from the amoeba to 
the encysted condition, a large central vacuole is discernible in the 
interior of the protoplasm which has taken up all the food-material, the 
original small vacuoles having gradually disappeared. When treated 
with alcohol, a distinct membrane could be detected surrounding this 
vacuole, which showed with chlor-zinc-iodide the characteristic reaction 
of cellulose. It follows that the digestion of the food can only be 
effected by an enzyme which dissolves the protein-substances, and these 
must then pass by diffusion through the membrane. The formation of 
this membrane seems to be constant in the Vampyrella examined ; but 
as the peculiarity appears to have a physiological rather than a morpho- 
logical value, the author proposes to treat it merely as a variety under 
the name Vampyrella vorax Cnk. var. dialysatrix. 
Spores of Myxosporidia.j — M. P. Thelohan finds that the spore of 
the Myxosporidia contains a small mass of protoplasm in which is 
differentiated a vesicle filled with a special substance, which resists 
colouring matters. There are present, moreover, nuclei which result 
from the division of a primitive nucleus ; the number of these varies in 
different forms of Psorosperms. The author is as yet unable to point 
out the significance of these facts, but it is certain that the appearance 
of the plasmic mass of these spores of Myxosporidia, with the vesicle 
that refuses to stain and the nuclei scattered in the protoplasm, recalls 
in a striking way certain phases in the development of the spores of 
* Ber. Deutsoh. Bot. Gesell., vii. (1889) pp. 277-9 (1 pL). 
t C'oniptes Rendus, cix. (1889) pp. 919-22, 
