i8 95 . THE LAST OF THE "CHALLENGERS' 319 



call it, occupies, with its details, the greater portion of both parts of 

 this volume, and it is copiously illustrated with charts of the route 

 beautifully engraved. At the first station the first attempts were 

 made at sounding and dredging, the object being chiefly to exercise 

 the seamen in the use of the apparatus. We read: " At 8.10 a.m. 

 took first sounding, and made first attempt at dredging. In hauling 

 in, the sounding line carried away, and a thermometer was lost. At 

 1 p.m. the dredge came up capsized," etc. Such was the beginning ! 

 However, a subsequent attempt at this station rewarded the voyagers 

 with two new species, one being a new generic type ; and these were 

 never obtained elsewhere. It would be impossible to exaggerate the 

 value of this great record of the voyage, enriched with notes from 

 the author's own journal and the manuscript journals of Moseley and 

 Willemoes-Suhm, and, of course, based on the official log and the 

 published reports. It forms the companion volume to the Narrative. 

 At the end of this great summary it is analysed in a series of 

 tables illustrating the bathymetrical and geographical distribution of 

 the organisms captured. The interest culminates in Dr. Murray's 

 general observations on the distribution of marine organisms, where 

 his extraordinary grasp of the bewildering mass of facts and observa- 

 tions is focussed and his views lucidly expounded. It would be vain 

 to attempt here even an outline of this colossal labour, but I cannot 

 resist making an extract dealing with Dr. Murray's speculative views 

 on the determining influence of the origin of climate on distribution. 

 Commenting on the strong resemblance between the north and south 

 polar marine faunas, and the absence of similar forms in a high pro- 

 portion of cases from the intervening tropical belt — a resemblance 

 extending to the pelagic flora, and even, as I have shown elsewhere, 2 

 to the more variable coast marine flora — the author submits the 

 following daring hypothesis. " In early mesozoic times cooling at the 

 poles and differentiation into zones of climate appear to have 

 commenced, and temperature conditions did not afterwards admit of 

 coral reefs in the polar area. But the colder and hence denser water 

 that in consequence descended to the greater depths of the ocean 

 carried with it a large supply of-oxygen, and life in the deep seas 

 became possible for the first time. There have been many specula- 

 tions as to how a nearly uniform temperature could have been brought 

 about in sea-water over the whole surface of the earth in early 

 geological ages, as well as to how sufficient light could have been 

 present at the poles to permit of the luxuriant vegetation that 

 once flourished in these regions. The explanation that appears 

 to me the most satisfactory is the one which attributes these 

 conditions to the very much greater size of the sun in the early stages 

 of the earth's history — an idea first introduced into geological specu- 

 lations by Blandet, who likewise discussed the relations of Arctic and 

 Antarctic faunas — together with the greater amount of aqueous 



2 Phycological Memoirs, part iii., 1895. 



