444 MICROSCOPY. 
It is with hesitation that I remark further that the fth has re- 
solved the lines of Amphipleura pellucida into rows of dots, for — 
the “beaded” structure of the easier test, Surirella gemma, is stil 
doubted by some experienced microscopists. But ‘facts are st : 
born things” and the facts are that with Wenham’s parabola a 
an illuminator the dots are seen, and with either the paraboloid ni 
the Amici prism longitudinal lines much finer than the tran 
ones are brought out. These lines, which I consider genuine, 
count not far from 120,000 to the inch. With a slight change of 
the adjustment their place is occupied by spurious lines countin 
generally about 60,000 to the inch. The longitudinal lines can 
only be seen when the focus is best adjusted for the transve 
striæ. When the transverse lines are examined, they may be 
shown smooth and shining, similar to. the photograph by. 
Woodward in the Naturatisr, but much better. If the mirror 
is then carefully touched a sinuate appearance of the margini A 
the lines suggestive of beading is seen. This appearance can be | 
brought out readily. And finally after the most painstaking 
manipulation, and when without doubt the best work is being ie" 
the separated dots or beads appear. —G. W. MOREHOUSE. 
yg 
On Crrcurarory Movement rw Vavonerta. — Prof. Leidy 
some remarks on the intra-cellular circulation of plants, 28 
plified in the hairs of the mullein, the leaf-cells of bere ip 
The moving streams of protoplasm he likened to am 
ments, and expressed the opinion that they were of te: 
character. In the common alga, Vaucheria, the filaments 
consist of very long cells, comparable to those of Nitella 0 
he had observed an apparent motion of the cell contents 
is somewhat peculiar and, at least, is not generally ment ; 
writers. The wall of the cells is invested on the interior’ 
layer of tenacious protoplasm, containing the thinner liguit 
contents as usual. The parietal protoplasm is closely paved 
green granules, and these appear very slowly but ince 
change their position in relation with one another. | 
so slow that it was a question for some time whether it did 
occur, but it appears sufficiently obvious if observed i 
with the lines of a micrometer, and its existence was C0! n 
several friends whose attention was directed to it— 
Academy of Natural Sciences, Philadelphia. 
