140 DISSEMINATION OF SEEDS. 



which retain their vitality and, under favorable circum- 

 stances, grow. 



Many aquatic birds build their nests on the ground far 

 from the water's edge and, being wanderers, must often 

 aid in the dispersal of seeds having hispid awns, hooks, 

 or prickles by which they become fastened to the feathers 

 of the birds. Some species of birds burrow in the soil 

 and in burrowing get their feathers covered with vegetable 

 mould which may contain seeds and spores in large 

 numbers. Earth often becomes attached to the plumage 

 of ground-nesting birds or to the feet of aquatic birds, and 

 Darwin has proved by actual experiment that all such 

 earth contains seeds. On page 328, " Origin of Species," 

 he says, "Although the beaks and feet of birds are gen- 

 erally clean, earth sometimes adheres to them 



The leg of a woodcock was sent to me by a friend, with 

 a little cake of dry earth weighing only nine grains at- 

 tached to the shank ; and this contained a seed of toad- 

 rush which germinated and flowered Prof. 



Newton sent me the leg of a red-legged partridge 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 three years, but when broken, 

 watered, and placed under a bell-glass, no less than eighty- 

 two plants sprang from it Willi 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 Mediterranean, must occasionally transport a few 

 seeds embedded in dirt adhering to their feet or beaks?" 

 . . . . " Wading birds wander more than those of any 

 other order. They frequent the muddy edges of ponds 

 and are most likely to have muddy feet. They are occa- 

 sionally found on the most remote and barren islands of 



