Fuly 16, 1885 | 
NATURE 
251 
distribution of temperature in this vast expanse of water. 
A series of soundings taken from lat. 4o° N. to lat. 4o° S. 
affords a section of the very centre of the ocean through 
upon a ¢a/ws of coral-rock broken off by the waves, and 
do not prove subsidence as was believed by Darwin. 
Among the corals, briefly described by Mr. Moseley, 
the volcanic peaks of Hawai and Tahiti. Perhapsno single | probably the most beautiful of the madrepores is the 
part of the sounding work of the expedition offers 
impressive example than this of the boldness and success 
with which the problems of the deep sea can now be 
attacked. Down the middle of the widest and deepest 
a more | delicatel 
ocean on the face of the globe a line of temperature | 
soundings is taken with as much precision as if it had 
been an inland lake, and information is obtained that 
furnishes a clear picture of the depth of the water, the 
form of the bottom, and the manner in which the layers | 
of different temperatures are superposed upon each other | 
from the surface downwards. A careful survey of the 
coral-reef of Tahiti by Lieutenant Swire and Mr. Murray 
suggested to the latter observer the view which he has 
already published—that this reef and coral-reefs in general 
may be formed by the outward growth of the living coral 
y fragile Leptofenus trawled from a depth of 
| 2,160 fathoms between Juan Fernandez and Valparaiso 
(Fig. 6). Prof. Hubrecht of Utrecht supplies some 
notes on the Vemertea in anticipation of his detailed 
Report on this subject. A summary is given of Mr. H. 
B. Brady’s studies of the Loraminifera, which are so 
abundant in the surface waters and play so important a 
part in the formation of deep-sea deposits ; and a digest 
of the Report of Dr. G. S. Brady on the copepod and 
ostracod crustaceans. But perhaps the most generally 
interesting section of this part of the narrative is that which 
treats of the nature of the organic deposits now forming on 
the floor of the deeper parts of the ocean. The important 
results obtained by the Challenger expedition in this novel 
department of enquiry have already been made familiar 
Fic. 6.—Lefptopenus hypocelus, Moseley. 
by the writings of Messrs. Murray and Renard. But the 
reader will be glad to have them re-stated in the official 
account of the voyage, and to find them so admirably 
illustrated with woodcuts and a lithographic plate, which 
enable him to realise exactly the nature of the evidence | 
for the extreme slowness of deposition at these great 
depths and so far from land. From no fewer than 116 
sharks’ teeth brought up with over two bushels of man- 
ganese nodules in a single haul from a depth of 2,385 
fathoms, Fig. 7 has been selected for illustration. It differs 
in no essential particular from the tooth of Carcharodon 
megalodon, so common in Tertiary strata, except that it 
shows no large base. 
Quitting Valparaiso, the Challenger pursues a southerly 
track to Port Otway, and then winding through the long 
line of sounds between the islands and the mainland pas- 
ses through Magellan Strait to the Falkland Islands, and 
thence to Monte Video. o 
we learn from Dr. Hoek what he has found out regarding 
During this part of the narrative | 
the Cirripedes and Pycnogonids obtained during the 
cruise; from Mr. F. E. Beddard regarding the Isopods ; 
from Mr. R. B. Watson about the Scaphopods and Gas- 
teropods; from Mr. J. R. Henderson about the Anomurous 
Crustaceans; from Dr. Giinther respecting the deep-sea 
fishes; and from Prof. E. Selenka regarding the Gephy- 
rea. The course is then shaped eastward from Monte 
Video, across the South Atlantic to Ascension, and during 
the account of this /raverse we are shown how the fora- 
miniferal deposits of the deep sea were collected and 
investigated, and are supplied with a useful summary of 
the results arrived at by Messrs. Murray and Renard 
regarding deep-sea deposits in general, illustrated with 
an excellent coloured plate, which, in default of the actual 
objects themselves, brings their characters very clearly 
before the eye. As the narrative proceeds with the 
account of the homeward voyage from Ascension, we are 
told about pelagic diatoms, marine infusoria, cocco- 
spheres, rhabdospheres, bathybius, and the land-plants 
