DISSEMINATION OF SEEDS. 139 



found abundantly along stone walls on which the birds 

 have rested. 



Sometimes the seeds of plants are taken into the stomach 

 and afterwards rejected in a fit state for germination. This 

 is true of the seeds of berries like those of the mistletoe 

 which the thrush swallows and afterwards deposits on the 

 boughs of trees adapted to the growth and development 

 of the plant. Seeds of currants are often swallowed by 

 the blackbird and one may occasionally see a currant bush 

 growing out of a tree upon which a seed was left by the 

 bird in an opening in which earth had collected. 



It is surprising that seeds have the power to resist the 

 heat and digestive action of the stomach of animals, but 

 it is undoubtedly the fact that some seeds seem to require 

 it. An English botanist tells us that seeds of the Mag- 

 nolia glauca carried to England refused to vegetate until 

 they had undergone this process. 



We are told that in England the brown linnet feeds 

 upon thistle seeds and, in trying to obtain them, "perches 

 on the top of the stalk and tears the downy head asunder 

 in order to reach the seeds which are attached to the 

 receptacle. During the act, many of the seeds are 

 loosened and carried away by the breeze to places far 

 distant from the parent stem, the bird being in this 

 instance the indirect disseminator of the thistle. Were 

 the head not rent asunder in this fashion it would most 

 probably be soaked by the rains of winter and tail down 

 only a few inches from the original stalk instead of being 

 transported, as it frequently is, across many miles of 

 country." " What is here told of the linnet," says Mac- 

 millan, "may be witnessed in any 'thistlery' on a fine 

 September day when the birds are feeding in flocks." 



Birds when they migrate from a colder to a warmer 

 climate or from a warmer to a colder often carry seeds 

 10* 



