158 NATURE TEACHING 



might also have been naturally brought from another 

 flower in addition to that from the one actually used. 

 Choose the flower to receive the pollen while still in the 

 bud-stage, before the anthers have ripened and any 

 pollen has escaped. Gently open the bud and remove 

 the stamens, either by cutting them out by means of 

 fine-pointed scissors, or by pulling off their heads by 

 means of forceps. Protect the flower, thus prepared, 

 from insect visits by covering it with a muslin or paper 

 bag, which may be conveniently fixed over a small branch 

 having upon it several prepared flowers. After a few 

 days the stigmas will be mature and ready to receive 

 the pollen. Then, temporarily remove the bags and 

 apply pollen from a selected flower to the stigmas. Re- 

 place the bags immediately, and leave them until the 

 flower fades. When this has occurred, remove the bags ; 

 tie a label near to the ripening fruit in order that it may 

 be identified. As before, raise plants from the seeds, 

 and compare them with their parents, this time definitely 



known. 



Dispersal of Seeds. 



The practical work on this subject must in the main 

 consist of observations made out-of-doors. Examine 

 the weeds which come up in the garden, and endeavour 

 to find out how they probably got there ; that is to say, 

 whether their seeds are likely to have been blown by the 

 wind, carried by birds and other animals, or introduced 

 in other ways. 



In addition to the weeds of the garden, the plants 

 growing on walls and in the hollows of trees for instance, 

 in the crowns of pollarded willows should be noted, and 



