THE WAY IN WHICH NEW PLANTS AIIISE 151 



thrown into the air in such quantities that it is 

 deposited upon the ground, making a " shower of 

 sulphur." 



206. Animals as I'^ollen carriers. — The flowers 

 of many species are provided with means of attrac- 

 tion to certain animals, principally insects, and dur- 

 ing their visits pollen adheres to their bodies and 

 is carried to the next flower. The attraction may 

 be nectar or honey, the pollen itself, a place for 

 the deposit of eggs, or the flower may offer the 

 insect a suitable place of refuge or lodgment for 

 the night or during a storm. The description of 

 the various methods by wdiich this is done would 

 fill a large book, and may not find place here. On 

 a favorable day in the spring or summer the student 

 should find a flower which is frequented by insects, 

 and note the manner in which this visit is made. 

 First determine the object of the visit. Then note 

 what parts of its body rub against the stamens and 

 pistils. Catch one of the insects, and examine its 

 body for traces of pollen. Examine a number of 

 flowers late in the evening or early in the morning 

 for animals which have lodged in them during 

 the night. 



