Dr. J. W. Spencer — The Yumuri Valley of Cuba. 499 



felspar crystals from specimens of rhomb porphyry from Laurvig 

 in the Natural History Museum. 



Now for two personal matters : — Mr. Deeley says I have misquoted 

 two letters of Professors Bonney and Hughes. The letters were 

 private letters, written to myself, and are on my table. How any- 

 one but myself and the writers can know what they contain T know 

 not. All I know is that Prof. Bonney, in regard to the Lofodens, 

 and Prof Hughes, in regard to the shipwrecked stones on the East 

 coast, absolutely confirm my statements of fact. The inferences 

 are my own. 



Secondly, Mr. Deeley says I sneer at official geologists. In my 

 case to do so would be like parricide and fratricide. I have learnt a 

 great deal of what I know from them, and have received unbounded 

 courtesy from them. What I do object to, and shall continue to 

 protest against, is the notion that geologists, official or otherwise, 

 any more than any other scientific men, have a right to publish and 

 discuss great issues until they have read what other people have written 

 about them. It does further seem preposterous to me that a number 

 of men should be told off to map so-called glacial deposits, and 

 to write memoirs — not on the facts, but on a glacial explanation 

 of the facts — who have never studied the mechanics of ice in the 

 laboratory, and, what is more strange, have never seen a glacier 

 at all. 



Lastly, I suppose no other science but long-suffering geology 

 would tolerate the absurdity — may I say the impertinence ? — of a 

 public advertisement from a casual visitor to Switzerland, that, 

 having gone to Mont Blanc in the year of grace 1894, he proposed 

 to settle the great question of the different action of neve and ice. 

 Why, the question is a century old, and there was a whole library 

 written upon it before either Mr. Deeley or myself was born ! 



YT. — The Yumuri Yalley of Cuba — A Eook-Basin. 



By J. W. Spencer, M.A., Ph.D., B.A.Sc, F.G.S. 



"\TEAR the city of Matanzas, in Cuba, there is a beautiful valley 

 ±\ called the Yumuri, of which the good people of the region 

 are justly proud. Its intei'est to the geologist is unsurpassed in the 

 island. At its entrance there is the most complete section of 

 Tertiary rocks observed by me in Cuba. This valley is a record 

 of the great erosion of the land during most of the Pliocene period, 

 at the close of which it was partly refilled. The valley was re- 

 excavated during the earlier days of the Pleistocene period, and 

 sufi"ered other changes, but it is the closing of the valley into a 

 rock-basin in almost modern days of which I write. 



Upon the northern side of the ridges, of which Pan de Matanzas 

 is the highest point (1277 feet above tide), there are the remains of a 

 former plain, which extended five or six miles to near the sea-shore, 

 with an elevation of about 450 feet. Out of this plateau the Yumuri 

 Yalley has been excavated with a breadth of about three miles, and 

 length of five or six miles, with a further rugged extension of one 



