328 Means of Dispersal Chap, xifi 



Although the beaks and feet of birds are generally clean, earth 

 sometimes adheres to them : in one case I removed sixty-one grains, 

 and in another case twenty-two grains of dry argillaceous earth 

 from the foot of a partridge, and in the earth there was a pebble as 

 large as the seed of a vetch. Here is a better case : the leg of a 

 woodcock was sent to me by a friend, with a little cake of dry earth 

 attached to the shank, weighing only nine grains ; and this con- 

 tained a seed of the toad-rush (Juncus bufonius) which germinated 

 and flowered. Mr. Swaysland, of Brighton, who during the last 

 forty years has paid close attention to our migratory birds, informs 

 me that he has often shot wagtails (Motacilke), wheatears, and whin- 

 chats (Saxicolee), on their first, arrival on our shores, before they 

 had alighted ; and he has several times noticed little cakes of earth 

 attached to their feet. Many facts could be given showing; how 

 generally soil is charged with seeds. For instance, 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 placed under a- 

 bell glass, no less than 82 plants sprung from it : these consisted of 

 12 monocotyledons, including the common oat, and at least one 

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

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

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

 blown by gales across great spaces of ocean, and which annually 

 migrate—for instance, the millions of quails across the Mediterra- 

 nean—must occasionally transport a few seeds embedded in dirt 

 adhering 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 autarctic regions ; and during the Glacial period 

 from one part of the now temperate regions to another. In the 

 Azores, from the large number of plants common to Europe, in com- 

 parison with the species on the other islands of the Atlantic, which 

 stand nearer to the mainland, and (as remarked by Mr. H. C. 

 Watson) from their somewhat northern character in comparison 

 with the latitude, I suspected that these islands had been partly- 

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

 Sir C. Lyell wrote to M. Hartung to inquire whether he had 

 observed erratic boulders on these islands, and he answered that ha 



