DISSEMINATION OF SEEDS. 143 



tached to the seeds themselves ; in Galiwn aparine, to the 

 pericarp; in the thistle and burdock, to the involucre ; in 

 Agrimonia, to the dry calyx. In some species of Geum, 

 the style becomes hooked at the tip for adhesion to the 

 fleece of animals. The jointed pods of Desmodium attach 

 themselves by means of minute hairs to the fleece of ani- 

 mals or .to clothing and are thus readily carried from 

 place to place. 



Squirrels, as before-mentioned, often hoard large quan- 

 tities of fruit, sometimes burying it in the ground and at 

 others in hollows in the trunks of trees. When this sup- 

 ply is discovered by an animal not caring for the fruit, it 

 is often scattered, and, coming in contact with the moist 

 earth, the seeds germinate. This means of the dispersion 

 of the seeds was noticed by the Indians, who had a tradi- 

 tion that squirrels planted all the timber of this country. * 



Certain quadrupeds, particularly the grass-eating, as 

 the reindeer which live on the plains of Siberia, and which 

 at certain seasons migrate in herds, assist in the disper- 

 sion of seeds. 



Darwin states that he found that many fresh-water fish 

 consumed the seeds of land and water plants, that these 

 fish were eaten by birds, such as the heron, and that by 

 the birds, as they took their flight and went to other wa- 

 ters, the seeds were transported, it might be, many miles 

 from the place where they were eaten by the fish. 



MAN THE DISSEMINATOR OF SEEDS. 



While birds and the lower animals are involuntary 

 agents in the distribution of seeds, man voluntarily and 

 purposely introduces plants from one country to another. 

 This he does from various motives, the most prominent 

 being the desire to cultivate useful plants and to beautify 



