308 
the outlines of the two Noctiluca-vesicles fuse, and thus the 
double spheroid or biscuit-shaped bladders are formed. By 
further fusion the pinching in of the vesicle disappears from 
one side, so that the vesicle becomes more nearly spherical. 
Meanwhile the two nuclei become completely fused into one, 
retaining, however, their radiating threads and network, as 
in normal individuals. The cross-striped “ lashes” and the 
“teeth” of the two fused Noctiluce also disappear. All 
trace of the double origin of these ‘‘ copulated Noctiluce” 
may pass away by the disappearance of the fold on the 
surface, near to which the nucleus lies, and thus a Noctiluca 
vesicle is formed, which is always larger than the normal 
Noctiluca, and seems identical with the bodies noticed by 
Busch, and also very probably identical with the biscuit- 
shaped and spherical Noctiluca vesicles in which Cienkowski 
has traced the formation of the swarm-spores. A direct 
observation of the formation of swarm-spores in the copulated 
forms Cienkowski was not able obtain. 
Ciliary Movement.—In the ‘Biologische Studien,’ his 
latest contribution to scientific literature, Professor Haeckel 
gives the result of some highly important observations on the 
nature of ciliary movement. ‘The most recent investigations 
on this subject, viz. those of Dr. W. Engelmann (‘ Jenaische 
Zeitschrift, 1868, vol. iv, p. 321), as also the earlier ones of 
Dr. M. Roth (‘ Virchow’s Archiv.,’ Bd. 37, p. 184), have 
shown that physiologically the ciliary is much more nearly 
related to the amceboid movement than to the muscular. 
Professor Haeckel’s observations show that the ciliary move- 
ment is merely a modification of the amceboid movement of 
protoplasm. Ciliated cells are of two kinds. In the one 
kind (epithelium flagellatum) each cell is provided with a 
single long flagellum or lash—sponges possess only this 
kind ; in the other (epithelium ciliatum), numerous hair-like 
appendages take the place of the flagellum. This is the 
kind found in most of the higher animals. The old notion, 
that in ciliated cells the cilia are attached tp the outside of © 
the cell membrane, must now be considered as entirely set 
aside. Many, probably most, ciliated cells are destitute of a 
membrane, and the appendages, whether flagella or cilia, are 
direct processes of the protoplasm of the cell. Professor 
Haeckel’s observations on lower organisms during the last 
year have led him to the conclusion that ciliated cells arise 
directly by the transmutation of ameboid cells. This trans- 
mutation he has observed in the case of the motus flagellaris, 
in Monera, such as Protomyxa anurantiaca and Protomonas 
