410 Miscellaneous. 
vesicles. Injection made though the ambulacral vessels does not 
generally pass the inner marginal vessel, except when the injection 
is made with a rather strong pressure. We then find that the 
vesicles are completely inflated by the material; by means of the 
pressure the latter has been able to traverse the tissue of the vesicles 
to penetrate into the superior ring. 
As in the Spatangi, there are two vessels in each ambulacral zone, 
a superficial and a deep-seated vessel, and each of them emits a 
branch to each ambulacral vesicle. These two vessels are indepen- 
dent of the nervous band which is closely applied to the wall of the 
test. At the level of the lower margin of the lantern the ambula- 
cral vessels, from being double, become simple, and ascend along 
the pyramids to debouch into the inferior ring. 
When an injection is made through the superficial ambulacral 
vessel or through the deep-seated one, the same result will be 
arrived at; that is to say, the inferior pericesophageal ring will be 
filled. 
Teuscher, who also admits the existence of two ambulacral ves- 
sels (although, according to him, one of them surrounds the nervous 
band), thought that in transverse sections of the pharynx he re- 
cognized the section of five vessels; he believed that these five vessels 
were the continuation in the interior of the lantern of his periner- 
vian ambulacral vessels, and that they opened into the superior 
pericesophageal ring. Now, these vessels do not exist, and the supe- 
rior esophageal ring is in communication with the ambulacral 
vessels only by the intermediation of the Polian vesicles. 
The anatomical arrangements of which I have just given a 
summary, namely the existence of two pericesophageal rings, the 
existence of two vessels in each ambulacral zone, the complete 
independence of the nervous and circulatory systems, and the com- 
munication of the excretory organ with the circulatory system by the 
intervention of the sand-canal, approach the facts which I have 
already indicated in the irregular Echinoidea.—Comptes Rendus, 
Sept. 4, 1882, p. 459. 
On Lieberkuehnia, a Freshwater Multinucleated Rhizopod. 
By E. Mavpas. 
When, in July 1879, I presented to the Academy a note on some 
multinucleated animal and vegetable protorganisms, I expressed my 
opinion that a number of new facts would certainly have to be 
added to those already known concerning multinucleated cells. 
Among the Algz I mentioned the group of Siphonez as being likely 
to possess the same structure. This supposition was no longer such 
at the time I expressed it, as, contemporaneously with my notice, 
there appeared in Germany a memoir by Fr. Schmitz, in which that 
skilful observer pointed out the plurality of nuclei in several of the 
Algze belonging to this group. Since then the researches of Treub, 
Berthold, Johow, and Guignard have still further increased the num- 
ber of cases of nuclear plurality in vegetable cells. 
