WORK OF THE PERIOD. 327 



interrupted elevation of the South American Continent 

 during a recent geological period." * 



Of this book my father wrote to Lyell : " My volume will 

 be about 240 pages, dreadfully dull, yet much condensed. I 

 think whenever you have time to look through it, you wilB 

 think the collection of facts on the elevation of the land and 

 on the formation of terraces pretty good." 



Of his special geological work as a whole, Professor Geikic,. 

 while pointing out that it was not " of the same epoch-making 

 kind as his biological researches," remarks that he "gave a 

 powerful impulse to " the general reception of Lyell's teaching 

 " by the way in which he gathered from all parts of the world" 

 facts in its support." 



WORK OF THE PERIOD 1842 TO 1854. 



The work of these years may be roughly divided into a 

 period of geology from 1842 to 1846, and one of zoology 

 from 1846 onwards. 



I extract from his diary notices of the time spent on his 

 geological books and on his ' Journal.' 



'Volcanic Islands.' Summer of 1842 to January, 1844. 



' Geology of South America.' July, 1844, to April, 1845. 



Second Edition of ' The Journal,' October, 1845, to October, 

 1846. 



The time between October, 1846, and October, 1854, was 

 practically given up to working at the Cirripedia (Barnacles) ;. 

 the results were published in two volumes by the Ray Society 

 in 1851 and 1854. His volumes on the Fossil Cirripedes were 

 published by the Palaeontographical Society In 1851 and 1854. 



Some account of these volumes will be given later. 



The minor works may be placed together, independently, 

 of subject matter. 



" Observations on the Structure, &c., of the genus Sagitta," 

 Ann. Nat. Hist, xiii., 1844, pp. 1-6. 



* Geikie, loc. cit. 



