250 
ISLAND LIFE. 
[part II. 
Birds as Seed-couriers . — The great variety of fruits that are 
eaten by birds afford a means of plant-dispersal in the fact that 
seeds often pass through the bodies of birds in a state well-fitted 
for germination ; and such seeds may occasionally be carried long 
distances by this means. Of the twenty-two land-birds found in 
the Azores, half are, more or less, fruit-eaters, and these may have 
been the means of introducing some plants into the islands. 
Birds also frequently have small portions of earth on their 
feet ; and Mr. Darwin has shown by actual experiment that 
almost all such earth contains seeds. Thus in nine grains of 
earth on the leg of a woodcock a seed of the toad-rush was 
found which germinated ; while a wounded red-legged partridge 
had a ball of earth weighing six and a half ounces adhering to its 
leg, and from this earth Mr. Darwin raised no less than eighty- 
two separate plants of about five distinct species. Still more re- 
markable was the experiment with six and three-quarter ounces 
of mud from the edge of a little pond, which, carefully treated 
under glass, produced 537 distinct plants! This is equal to a 
seed for every six grains of mud, and when we consider how 
many birds frequent the edges of ponds in search of food, or 
come there to drink, it is evident that great numbers of seeds 
may be dispersed by this means. 
Many seeds have hispid awns, hooks, or prickles which readily 
attach them to the feathers of birds, and a great number of 
aquatic birds nest inland on the ground ; and as these are pre- 
eminently wanderers, they must often aid in the dispersal of 
such plants. 1 
1 The following remarks, kindly communicated to me by Mr. H. N. 
Moseley, naturalist to the Challenger , throw much light on the agency of 
birds in the distribution of plants : — “Grisebach {Veg. derErde , Yol. II. p. 
496) lays much stress on the wide ranging of the albatross (Diomedea) 
across the equator from Cape Horn to the Kurile Islands, and thinks that 
the presence of the same plants in Arctic and Antarctic regions may be 
accounted for, possibly, by this fact. I was much struck at Marion Island 
of the Prince Edward group, by observing that the great albatross breeds 
in the midst of a dense, low herbage, and constructs its nest of a mound 
of turf and herbage. Some of the indigenous plants, e.g. Acsena, have 
flower-heads which stick like burrs to feathers, &c., and seem specially 
adapted for transportation by birds. Besides the albatrosses, various 
species of Procellaria and Puffinus, birds which range over immense dis- 
