100 THE DISTRIBUTION OF SEEDS. 



can attest from observation that there are few plants so repulsive 

 to taste or so spicy that they are not occasionally appropriated 

 by animals, according to the extremity of their hunger. I used 

 to think that nothing but starvation could induce cattle to nibble 

 at horrid opuntias, as I have seen them doing during drought. 



The mesquite tree, Prosopis juliflora, of the southwest is 

 worthy of especial mention. It is a godsend to those regions. 

 Its abundant and nutritious pods, resembling those of our field 

 bean, begin to fall in August before the grass has made much 

 advance under the midsummer rains, and afford much relief to 

 the half famished stock. I have gathered sacks full of them for 

 my horses as I have journeyed through those arid districts. 



Seeds are Distributed in a great variety of ways through 

 the agency of wind, water, snow, animals, including man him- 

 self, who purposely or unintentionally accomplishes more than 

 any of the other agents. 



The small size of the seeds of most grasses is a great help in 

 their distribution. Many of them remain attached to the glumes 

 and palea, or even to some of the branches, and others are pro- 

 vided with beards, hooks, or awns, all of which make it easy for 

 them to be carried about by the wind, water, snow, or animals. 



" It would seem that nature has appointed every animal as a 

 special disseminator of the plants which furnish it with food. 

 We have seen the activity of the rodent in scattering the fruits 

 of the Nuciferae, and of birds in sowing broadcast the seeds of 

 fruit-bearing plants, and the ruminants seem no less active in 

 performing a similar work for their favorite grasses. The great 

 efficiency of animals as disseminators of seeds appears more 

 marked when we regard them in masses. The herds of reindeer 

 and elk on the plains of northern Europe and Asia, the bison on 

 the prairies of North America, or the herds of naturalized horses 

 and cattle on South American pampas, migrating from place to 

 place in immense masses, cannot fail to sow as they pass along a 



