332 LUTHER BURBANK 



common enough in nature. But so extreme a 

 case as that of the yucca and the insect that is its 

 inseparable associate is seldom duplicated. 



The insect in question is a little yellowish 

 white moth, so unfamiliar that it probably has 

 no colloquial name, but known to the entomolo- 

 gist as the Pronuba yuccasella. If you were to 

 watch closely you might see these moths visiting 

 the flowers of the yucca in the twilightc You 

 would require exceptional opportunities for ob- 

 servation if you were to discover precisely what 

 takes place during this visit. But entomologists 

 have kept watch to good purpose, and the terms 

 of the extraordinary coalition between the yucca 

 and the pronuba moth are now an open secret. 



It appears that the female moth that visits the 

 yucca blossoms has developed a long ovipositor 

 with which she can pierce the tissues of the ovary 

 of the plant and so lay her eggs within it. Her 

 prime object in visiting the yucca flower is thus 

 to deposit her eggs. In due course the eggs 

 hatch and the growing seeds of the yucca will 

 furnish them a supply of food. So there is 

 nothing very remarkable about this part of the 

 procedure. 



The surprise comes when we learn of certain 

 maneuvers preliminary to the deposit of the eggs. 

 If you could watch the little moth on her visit to 



