DISPERSAL AND PROTECTION xix 



Doubtless your own experience with burdocks, 

 agrimony, sticktights, and beggar ticks has 

 been sufficiently emphatic to render unnecessary 

 further mention of those fruits or seeds which, 

 fastening themselves to men and animals, are 

 carried by them hither and thither. Plants 

 bearing such fruits naturally grow most pro- 

 fusely by the side of the road or footpath. 



Animals and especially birds are instrumental 

 in scattering seeds in still another way, using a 

 part of the fruit for food and ejecting the seeds. 

 It is this class of fruits with which this book is 

 chiefly concerned. 



That seed dispersal is accomplished by the 

 means noted above has been a matter of dispute 

 among botanists, but carefully conducted experi- 

 ments have proved, without a doubt, that many 

 birds eject the consumed seeds unharmed. Inter- 

 esting accounts of these are given in Kerner and 

 Oliver's " Natural History of Plants." 



It has been found that while some birds grind 

 up and destroy even the hardest coated seeds, 

 others, like the ravens and jackdaws, destroy 

 only the soft-coated seeds ; while thrushes and 

 blackbirds eject unharmed a large majority of 

 the seeds eaten. The small seeds pass entirely 

 through the intestinal tract while the larger 

 ones are separated from the pulp in the crop, 



