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[APRIL 1, 1897 
COCCOSPHERES AND RHABDOSPHERES. 
HERE have been few more enduring puzzles in 
natural history than the nature of the Coccoliths, 
described by the late Mr. Huxley from Captain Day- 
man’s deep-sea soundings in the North Atlantic in H.M.S. 
Cyclops in the summer of 1857. Dr. G. C. Wallich, who 
was on board H.M.S. Sud/dog, engaged in a preparatory 
survey of the route for a telegraph cable about the same 
date, observed the aggregation of the Coccoliths into 
spheres, to which he gave the name of Coccospheres. He 
also pointed out the identity of the Coccoliths with 
bodies observed m chalk by Mr. Sorby. Mr. Huxley 
associated them with that unfortunate organism Bathy- 
bius. “1am led to believe that they are not independent 
organisms, but that they stand in the same relation to 
the protoplasm of Aa/hyécus as the spicula of Sponges 
or of Radiolaria do to the soft part of those animals” 
(Quart. Journ. Micr. Sci., vol. viii. N.S. p. 210, 1868). 
Prof. Haeckel, who received some ooze dredged by 
Wyville Thomson and Carpenter (Porcupine Exped.), 
put a like interpretation on the phenomena, and pub- 
lished in the Jenatsche Zettschrift, vol. v., 1870, a de- 
tailed account of the matter with illustrations. Bathydbzus 
is dead, but one cannot leave it without the reflection 
that there are few naturalists, the young and expert 
included, but would have given similar explanation of 
the appearances. The Challenger Expedition next 
entered the field, and discovered Coccospheres and 
Rhabdospheres on the surface of the ocean, living free 
in the water, entangled in the protoplasmic matter of 
Foraminifera and Radiolarta, and in the stomachs of 
Crustacea and Salp@. The Rhabdospheres are known 
only from the tropics, and the Coccospheres, though 
tropical as well, yet find their finest development in 
temperate seas. ‘‘ There is considerable variety both 
in the form and size of Coccospheres and Rhabdo- 
spheres, some varieties having the component parts 
(Coccoliths and Rhabdoliths) much more compactly 
united into a sphere than others. The interior of the 
spheres is perfectly clear when examined fresh from 
the surface, and becomes coloured brown with iodine 
solution, but with iodine and sulphuric acid no blue 
colour was observed. They were never observed to 
colour with carmine solution. When the calcareous 
parts are removed by dilute acids, a small gelatinous 
sphere remains, in the outer layer of which the Cocco- 
liths and Rhabdoliths were embedded” (Challenger 
Reports, “ Narrative,” vol. i. p. 939). 
on the Deep-Sea Deposits, Dr. John Murray treats 
them as pelagic calcareous alge (p. 257), and one of 
us has been criticised with some severity for adopting 
this view in an “ Introduction to the Study of Seaweeds.” 
The Hensen Plankton Expedition, probably through 
using silk nets of too coarse a texture, failed altogether 
to find Coccospheres or Rhabdospheres, and Dr. Schiitt, 
the botanist of that expedition (“Pflanzenleben der 
Hochsee,” p. 44), casts doubt on their very existence as 
organisms, and in any case will have none of them in 
the vegetable kingdom. Many other naturalists, wise 
and eminent, British and foreign, have shared, and do 
share, the opinion of Schiitt. 
What the Hensen Expedition failed to discover has 
been effected, however, by quite simple means. A few 
years ago, Dr. John Murray, while crossing the North 
Atlantic, obtained the Coccospheres again by simply 
pumping sea-water through a very fine silk bag. He 
observed them carefully, and noted their contents to be 
yellowish, of much the same colour, he now informs us, 
as the diatoms. While using such a bag last year in 
diatom work on the Garland, it occurred to one of us 
that Coccospheres and Rhabdospheres might be obtained 
by this method in the hands of some enterprising 
mariner. Captain Haultain Milner, of the Royal Mail 
NO: 143i, VOE-55)] 
In the Report | 
steamship Parva, to whom natural history owes many 
debts, readily consented to put the method to the proof ; 
and, after rehearsing his part in the laboratory of the 
Botanical Department of the British Museum, sailed 
last January, equipped with a fine silk bag, tubes 
with non-acid fixing and preservative fluids, funnels, 
&c., for the port of Barbados. He was instructed 
that it would be sufficient to pump for a short time 
daily with the ordinary deck-hose (intake pipe, three 
fathoms deep) through the silk bag, and to transfer the 
residuum to the tubes containing the fixing and presery- 
ative fluids. Captain Milner has carried this out, pump- 
ing daily in the region agreed upon. It is interesting 
to observe that Coccospheres abound in the first day’s 
capture (lat. 41°30 N. long. 19:40 W.)—the method suc- 
ceeded in his hands in the most deadly way—and he 
subsequently obtained, in the tropical part of his voyage, 
both forms of Rhabdospheres figured by the Challenger 
Expedition. He got, in fact, not only what the German 
expedition failed to find any trace of, but all the three 
forms figured in the Challenger Report. 
In Fig. 1, @ and 4, there are copied from the Challenger 
Narrative” a Rhabdosphere and a Coccosphere. The 
Coccosphere figured was obtained from the bettom, and 
“ 
sl 
Fic. 1.—a, Rhakdosphere X 250; 2, Coccosphere x 500 (after Challenger 
Report). 
shows a disorganised condition.. The plates composing 
the shell of the Rhabdosphere are represented as fitting 
into each other with geometrical regularity. In the 
specimens we have seen and been able to examine, not 
on the heaving deck of a ship at sea, but with the re- 
sources and apparatus of modern research, the structure 
of the shell appears in each case different from that 
given in the Challenger Report. Fig. 2, A, represents a 
Coccosphere, as we see it, and a very minute and elusive 
microscopic object it is, under a 1/12th aprochromatic 
objective. The calcareous scales (or Coccoliths) overlap 
each other, and constitute not only an excellent defensive 
armour, but from their arrangement admit of the growth 
of the organism, which is not thus limited by its cal- 
careous coat, as the diatoms are by their siliceous shells. 
Each Coccolith is attached to the cell by a button-like 
projection on its inner surface. A figure nearly re- 
sembling ours occurs in Challenger Reports, “ Deep-Sea 
Deposits,” plate xi. Fig. 3. In the Rhabdosphere, with 
projecting rods shown in Fig. 2, b, C, the plates (Rhab- 
doliths) do not fit into each other in the manner figured 
in the Challenger Report, but their bases or bed-plates 
are embedded on the surface of the cell, each by itself 
without contact. This may be, on the one hand, a 
