PKEFACE. 
During the Voyage of the Challenger, the collection, examination, and 
preservation of all the samples of deposits were undertaken by Mr. Murray. 
Mr. Murray had also charge of all the work carried on by means of tow- 
nets in the surface and sub-surface waters of the ocean, and gave much 
attention to the part played by pelagic organisms in the formation of marine 
deposits. During the voyage he submitted the results of his work in this 
direction to Sir Wyville Thomson, and the results are referred to in several 
of the Reports of Sir Wyville to the Hydrographer of the Admiralty, 
published in the Proceedings of the Royal Society of London.^ 
Towards the close of the Cruise a Preliminary Report was prepared by 
Mr. Murray on the Deposits and Surface Organisms, and published in the 
Proceedings of the Royal Society of London.^ 
On the return of the Expedition to England, Mr. Murray continued the 
examination of the large collections that were brought home, and published 
some papers dealing with the results of his work.^ 
In the year 1878 Professor Renard was invited by Sir Wyville Thomson 
to assist Mr. Murray in the examination and description of the Challenger 
collection of marine deposits, especially with reference to the mineralogical 
and petrographical aspects of the subject. Subsequently it was arranged 
that a Report on all available samples of Deep-Sea Deposits, whether 
collected by the Challenger or otherwise, should be published conjointly by 
Mr. Murray and Professor Renard. 
During the years 1881 and 1882 Professor Renard spent several months 
in Edinburgh, when a large number of the deposits in the collection were 
examined in great detail, and the methods of examination and the order of 
1 See Proc. Roy. Soc., vol. xxii. p. 423 ; vol. xxiii. pp. 32 and 245 ; vol. xxiv. pp. 33, 463, and 623. 
2 Proc. Roy. Soc., vol. xxiv. pp. 471-544, 1876. 
* “ On the Distribution of Volcanic Debris over the Floor of the Ocean,” &c., Proc. Roy. Soc. Edin., vol. ix. j^p. 
247-261, 1876; “On the Structure and Origin of Coral Reefs and Islands, ibid., vol. x. pp. 505-518, 1880. 
(deep-sea deposits chall. exp. — 1891 .) 
h 
