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PEOGEESS OF MICEOSCOPICAL SCIENCE. 
The \Challenger' Beport on the GlohigerincB-ooze. — In a recent 
number of the Eoyal Society ' Proceedings ' (No. 170), there has 
been a Report of the ' Challenger ' expedition, which fills the entire 
number. In this, among other things, the following remarks occur 
in respect of the Glohigerina-ooze. The reporter, Mr. J. Murray, 
says that after the deep-sea clays this is the most abundant deep-sea 
deposit. It has occurred at all depths from 250 fathoms to 2900 
fathoms. The Glohig evince, which give at once the name and the chief 
characteristic to this deposit, are really found all over the bottom of 
the ocean. Even in our deepest clays, if the surface layers be 
selected and all the amorphous matter be washed away, one or two 
shells of some variety of pelagic Foraminifera can usually be detected. 
By pursuing this method I have only failed on one or two occasions. 
They appear to be quite absent in the Arafura Sea. It is, however, 
when they occur in vast numbers that they form the deposit known by 
this name ; at least such is the sense in which it is here used. 
We did not find a Glohigerina-ooze in any of the enclosed seas, in 
the Southern Ocean south of lat. 60° S., nor in the North Pacific 
north of lat. 10° N. 
In the Southern Ocean only one small species of Glohigerina was 
found in the surface waters ; but in the North Pacific many varieties 
of pelagic Foraminifera abound near the surface of the ocean. 
In other parts of the preceding oceans, and in the other oceans we 
have visited, it occurs in irregular patches, being always present in 
the ocean when we have depths of less than 1800 fathoms. Its pre- 
sence or absence at depths beyond 1800 fathoms is, however, deter- 
mined by conditions at present unknown. A number of varieties 
occur both as to colour and composition. Some specimens are nearly 
pure white, others have a rose colour, and others are red or dark 
brown. The red and brown colour arises from the presence of the 
oxides of iron and manganese. In the white varieties the sediment, 
after dissolving away the carbonate of lime, is in some specimens 
abundant, in others not abundant, and is either of a red or slate-blue 
colour. We find the former colour to prevail in those soundings far 
from continents and large islands, and the sediment is not abundant 
except where pumice or scoria is present. The latter, or slate-blue 
colour, is found in those soundings more or less near continents and 
large islands; and it is suspected that this sediment has its source 
chiefly from the disintegration of these adjacent lands. 
Mica, quartz, pumice, scoria, and other mineral particles are met 
with ; but in those soundings farthest from land a little piece of 
pumice or scoria may be the only trace of mineral particles. 
In some specimens there are very many remains of organisms with 
silicious shells, as Radiolaria, Diatoms, and Challengerias ; but in 
others these remains are almost entirely wanting. In three soundings 
in mid-Atlantic between the Canary and Virgin Islands, and in 
