142 DISSEMINATION OF SEEDS. 



rels are known to carry to pine forests stores of acorns 

 and other nuts and there conceal them for future use. In 

 some cases the squirrels are killed ; in others they neglect 

 to return to the storehouse ; and the result is the germi- 

 nation of many of the seeds in the succeeding spring. 

 For this reason, we often find little oaks and hickories 

 springing up in pine forests, and, if the pines are cut 

 down or in any way destroyed, the trees which have al- 

 ready commenced to grow will assert themselves, and the 

 hard woods will succeed the soft. 



William Bartram, an American naturalist of the last 

 century, wrote as follows : — " The jay is one of the most 

 useful agents in the economy of nature for disseminating 

 forest-trees and other nuciferous and hard-seeded vege- 

 tables on which they feed. Their chief employment dur- 

 ing the autumnal season is foraging to supply their winter 

 stores. In performing this necessary duty they drop 

 abundance of seed in their flight over fields and hedges 

 and by fences on which they alight to deposit the seeds 

 in the post-holes, etc. It is remarkable what numbers of 

 young trees rise up in fields and pastures after a wet win- 

 ter and spring. These birds alone are capable in a few 

 years' time to replant all the cleared lands." 



DISSEMINATION BY ANIMALS. 



Many seeds attach themselves, by means of hooks and 

 hairs, to the bodies of animals which come in contact with 

 the plant in their search for food, and thus become invol- 

 untary agents in the dissemination of the seed. The 

 hooks or hairs serve as points of attachment, and by them 

 the seed remains fixed so that it may be carried about by 

 the animal until detached by some accident and committed 

 to the soil. In Bidens and Myosotis, the hooks are at^ 



