Chap. XI. MEANS OF DISPERSAL. 335 



there was a pebble as larf^e as the seed of a vetch. Here is a 

 better case : the h\2: <if a woodcock was sent to mo by a friend, 

 with a little cake of dry earth attached to the sliaiik, weighini^ 

 only nine 2,rains ; and this contained a seed of the toad- 

 rush (Juncus bufonius) which germinated and flowered. Mr. 

 Swaysland, of Brighton, who has paid such close attention to 

 our migratory birds during the last forty years, informs me that 

 he has often shot wagtails (motacilla?)', wheatears, and whin- 

 chats (saxicoloe), on their first arrival, before they had alight- 

 ed on our shores, and has several times noticed little cakes of 

 earth on their feet. Many facts could be given showing how 

 the soil is almost everywhere charged with seeds. For in- 

 stance. Prof. Newton sent me the leg of a red-legged partridge 

 (Caccabis rufa) which had been wounded and could not fly, 

 with a ball of hard earth adhering to it, and weighing six and 

 a half ounces. The earth had been kept for three years, but 

 •when broken, watered, and jilaced under a bell glass, no less 

 than 82 plants sprung from it: these consisted of 13 monoco- 

 tyledons, including the common oat, and at least one kind of 

 grass, and of 70 dicotyledons, which consisted, judging from 

 tlie young leaves, of at least three distinct species. With such 

 facts before us, can we doubt that the many birds which are 

 annually blown l)y gales across great spaces of ocean, and which 

 annually migrate — for instance, tlie millions of quails across 

 the ^Mediterranean — nuist occasionally transport a few seeds 

 embedded in dirt adiiering to their feet or beaks ? But I shall 

 have to recur to this subject. 



As icebergs are known to be sometimes loaded with earth 

 and stones, and have even carried brushwood, bones, and the 

 nest of a land-bird, it can hardly be doubted that they must 

 occasionally, as suggested by Lyell, have transported seeds 

 from one part to another of the arctic and antarctic regions ; 

 and, during the Glacial period, from one part of the now tem- 

 Ijcrate rcgiims to another. In the Azores, from the large 

 number of plants common to Europe, in comparis(m with the 

 species in the otlier islands of thi^ Atlantic, which stand nearer 

 to the main-land, and (as remarked by Mr. H. C Watson) from 

 their somewhat northern character in comj^arison with the lati- 

 tude, I suspected that th(>S(^ islands had been partly stocked 

 by ice-borne seeds, during the Glacial epoch. At my request 

 Sir C. Lyell wrote to M. llartung to incjuire whether he had 

 observed erratic bowlders on these islands, and he answered 

 that lie had found large fragments of granite and other rocks, 



