ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
569 
employs in eliminating the clay from the organisms in diatomaceous 
earths, &c. It consists in triturating and rubbing them down on a 
sheet of rubber. The preliminary step in the cleaning is the breaking 
down of the clay in a soap-bowl containing water, which is several 
times poured off and renewed. The pellet of heavier sediment resulting 
from this treatment is then spread out and triturated on the rubber 
sheet. Finally the material is again transferred to the soap-bowl, and 
the washing with water continued until all the clay has been eliminated 
and the diatoms left, only mixed with sand-grains. To remove the 
diatoms from the sand, the customary concentration method may be 
used. In the case of marine clays, by the concentration method, the 
diatoms are left mixed with a large amount of vegetable debris difficult 
to reduce in the boiling acids. For such clays the author uses the 
following method : — The diatomaceous material, as roughly concentrated, 
is transferred to a wooden butter-holder, or hemispherical rubber cup, 
which is made to spin round rapidly by a smart flip of the finger. The 
contained liquid will rise up and spread round the sides, and the heavier 
sand and vegetable debris will settle back at once, leaving a cloud of 
diatoms in suspension. The bowl is then tilted to throw the diatoms to 
one side, and several pipettes full of liquid are quickly removed. The 
diatoms which settle from the liquid thus removed may be dried at once 
and mounted without treating with acid. 
Long Lines as Zoological Collecting Apparatus.* — Prof. Ijima 
gives an account of the use of long fishing lines as a means for collect- 
ing zoological specimens. It may be safely asserted that almost all the 
hexactinellid sponges hitherto known to inhabit Sagami Bay were brought 
to light through the medium of “ dabo lines. There are in the Zoo- 
logical Institute of the College at Tokio many still new to zoologists, 
some of which are of such exquisite beauty as to fascinate every eye, 
while others are of truly handsome dimensions. One is no less than 
875 mm. long and 270 mm. broad at the middle. Other kinds of sponges 
obtained by the same method are likewise rich in both individuals and 
species. A valuable collection of various forms of Hydrozoa and 
Anthozoa has been made for the Science College Museum since the 
Japanese fishermen have taken to dabo lines. Among Echinoderms, 
brittle-stars are the most frequently caught, but such rare and peculiar 
genera as Asthenosoma and Pourtalesia have also been dredged. Most inter- 
esting holothurians and crinoidshave also been taken. Many crustaceans 
have been taken, and for the famous giant crab, dabo lines appear to be 
the only apparatus that brings it up from the abyss. Both simple and 
compound Tunicates, as well as Brachiopoda, are also fairly well repre- 
sented among the trophies of the dabo lines. As may be supposed, 
worms and molluscs are the least favourable for dabo lines to catch hold 
of, although rare and remarkable specimens have thus been taken. 
Although we have not said as much as Prof. Ijima, yet we have 
said enough to show that the dabo lines can be of immense service to 
zoologists. The process is comparatively simple and inexpensive; it 
enables the dredger to reach a tolerably great depth where dredging and 
trawling can only be managed by steam power, and where, if the bottom 
* 
2 R 
1806 
Z.ol. Mag , viii. (189G) pp. 13-17, 19-23, 39-16. 
