P. KIDD ON SPONTANEOUS MOVEMENT OF NUCLEOLI. 133 
it is impossible, perhaps, to say with certainty. It is, 
however, a very pretty object under the microscope. 
There were besides on the leaves irregular bullate bodies 
(fig. 2) resembling Cystopus, but without any trace of fruc- 
tification. It is not, however, supposed that these parasites 
are really in the first instance injurious, as they are produced 
only on the leaves when they are so far advanced that they 
are useless for any economic purpose, though it is possible 
that if they occurred to any great extent they might have 
some influence on the product of the succeeding year, and 
the same is possibly the case with the thread blight. 
OBSERVATIONS om SPONTANEOUS Movement of Nuc L£o.t. 
By P. Kipp. 
DurinG an examination of the ciliated epithelial cells from 
a frog’s mouth Dr. Klein drew my attention to certain cells 
with special characters to be referred to presently, the 
nucleoli of which exhibited a crenated appearance; this 
aroused the suspicion of this being due to amceboid move- 
ment. ‘They were therefore subjected to a continuous and 
careful observation, and it was found that this was actually 
the case, viz., that these nucleoli perform spontaneous move- 
ment. In an ordinary saline solution preparation in which 
these movements were observed they were, although distinct, 
yet not very marked, and it was therefore desirable to repeat 
the experiment under more favorable conditions. A por- 
tion of epithelium from the same frog’s mouth was prepared 
between two thin cover-glasses, in a drop of ‘‘ humor aqueus” 
and a thin layer of oil was then painted round the edges of 
the cover-glasses. ‘The specimen was then placed on a 
Stricker’s warm-stage, and examined under a No. 10 immer- 
sion of Hartnack. The temperature of the warm stage was 
about 39° C. Several cells were again found similar to those 
before noticed, viz., cells differing from the other epithelial 
cells in having no cilia, in their distinct outline and large 
size, and in the pale and uniformly granular nature of their 
protoplasm. ‘They possessed a large ovoid vesicular nucleus 
like the other epithelial cells present, and were provided with 
a large nucleolus, sometimes with two nucleoli. The larger 
nucleoli measured 0:002 mm., the smaller 0°0015 mm. in dia- 
meter. As far as morphological characters go these cells 
