80 ON VEGETABLE PHYSIOLOGY. 



again are covered with a spiral awn or spring, 

 blended with a number of minute hairs which 

 serve as so many fulcra, by which they cling to 

 whatever objects come in their way; and the 

 seed, thus attached, is kept in continual motion 

 until it falls and germinates, or dies in the ground. 

 Thus cattle, to which it frequently fixes itself, 

 by moving from place to place, and depositing 

 the seeds over a large space of ground, are often 

 the instruments of this kind of distribution. 



In other instances, a dispersion takes place 

 from birds and other animals feeding upon the 

 fruits of plants, and dropping the seeds after they 

 have devoured the pulp. Some carry them away 

 to a particular spot to make a hoard of them ; 

 and such as are not consumed, germinate and 

 become plants. Others swallow the seeds, and 

 afterwards deposit them in the soil without being 

 injured. Our own species, we know, not onl 

 distribute the seed peculiar to our native climate, 

 but also bring from the most distant regions the 

 productions of foreign countries, and naturalize 

 them to our own. 



The winds, also, are another very powerful agent 

 in the distribution of those seeds which are pur- 

 posely constructed to be acted upon by their 

 influence; as the lichens and other seeds which 

 float invisibly in the air, and vegetate wherever 

 they happen to meet with a suitable soil. Some 

 are furnished with a light down, others by a 



