VIEWS OF ME. MUEEAY. 
283 
to some extent by tlie adventitious prominence which, 
during the last two or three years, has been given to certain 
valuable and interesting communications on this subject. 
Of the papers selected I have given a fairly full abstract, 
which represents, to the best of my ability, the views of 
their authors, whichever side they may have espoused, so 
that I trust the reader will be enabled to understand the 
present state of this difficult question, and to appreciate 
the reasons which have led some very competent authorities 
to maintain, and others to reject, the theory advanced by the 
late Mr. Darwin. 
It is true that, as I have stated in the conclusion, the 
close study of the question has not materially altered the 
view which I entertained when I began the task, but I have 
done my best to make my abstract a fair statement of each 
writer’s case. If, then, it should appear to any one that I 
ought to have given more prominence to this point and 
less to that, I may fairly plead that this has resulted from 
deficient apprehension, and not from conscious bias. I 
have placed first, arranging them chronologically, the 
papers which are more or less unfavourable to the dis- 
tinctive feature of Mr. Darwin’s theory ; then those which 
in the main support it. 
The following is a summary of Mr. Murray’s 1 views : 
Very nearly all oceanic islands, other than coral atolls, are 
now known to be of volcanic origin. Hence it is probable 
that the foundations of the latter are volcanic rocks and not 
those indicative of an ancient and pre-existent land. As 
shown by the soundings of the ‘ Tuscarora’ and ‘Challenger,’ 
numerous submarine elevations exist which rise from depths 
of 2,500 to 3,000 fathoms to within a few hundred fathoms 
of the surface. The upper water of the ocean (to a depth, 
1 On the Structure and Origin of Coral Eeefs and Islands. By 
John Murray. Proc. E. S. Edin. (1880), vol. x. p. 505. 
