296 LIFE AT DOWN. iETAT. 33-45. 



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 Octo- 

 ber, 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 185 1 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. i-6. 



" Brief Descriptions of several Terrestrial Planarise, &c.," 

 Ann. Nat. Hist, xiv., 1844, pp. 241-251. 



'' An Account of the Fine Dust * which often Falls on 

 Vessels in the Atlantic Ocean," Geol Soc. Journ. ii., 1846, pp. 

 26-30. 



"On the Geology of the Falkland Islands," Geol. Soc. 

 Journ. ii., 1846, pp. 267-274. 



'' On the Transportal of Erratic Boulders, &c.," Geol. Soc. 

 Journ. iv., 1848, pp. S^SS^S-^ 



* A sentence occurs in this paper of interest, as showing that the author 

 was alive to the importance of all means of distribution : — " The fact that 

 particles of this size having been brought at least 330 miles from the land 

 is interesting as bearing on the distribution of Cryptogamic plants." 



f An extract from a letter to Lyell, 1847, is of interest in connection with 

 this essay : — " Would you be so good (if you know it) as to put Maclaren's 



