1885. ] Zoology. 611 
observed lost its bluish tint and became of a bronze color. About 
an hour and a half after the conjugation it stopped suddenly, 
assumed a flat spread-out condition, whilst at the same time large 
vacuoles appeared throughout its entire mass. In appearance it ` 
was amoeba-like, and after a time small masses became detached 
and immediately assumed a globular form. The detachment of 
masses whilst in this amceba-like stage in other specimens was 
witnessed, as also their development into mature forms. 
The main mass would in some instances disintegrate after por- 
tions had been detached to form new individuals, nearly all the 
production by the formation of internal embryos was also observed, 
likewise the rarer method of fission proper. 
Professor Worcester considers the primitive form to be that of 
a sphere, and that the series of later forms assumed are so taken 
on by the creature in order to adapt itself more fully to its environ- 
ment. The posterior end would seem to be appended more for 
locomotion and for the purpose of fixing itself. Conjugation 
must in some way play an important part in the re-arranging of 
the protoplasm.— Yournal of the Royal Microscopical Society, De- 
cember, 1884. 
A Nervous System IN Sroxces.—Dr. R. v. Lendenfeld de- 
scribes the presence of nervous elements and ganglion cells in the 
heteroccelous sponges, In the Sycones the walls of the pores 
contain groups of spindle-shaped cells, mesodermal in origin, 
which are frequently connected with branched cells, apparently of 
tinuously grown to the mantle, the organic substance of the 
mother-of-pearl layer forms a net-work. Only Cyclas represents 
