Queer Friendships 



might be feasible were it allowed that insects are endowed 

 with feelings ; but, on the other hand, the plant certainly 

 cannot feel any emotion whatever. The case of the moth 

 and the yucca plant, often called Adam's needle, is so 

 extraordinary, and plant and moth are so perfectly 

 dependent on one another, that we make no excuse for 

 introducing them here. So interdependent are they 

 that without the moth the plant would never form seeds, 

 whilst the larvae of the moth can only exist upon the 

 seeds of this one kind of plant ; both moth and plant are 

 constructed for their mutual aid. 



On the head of the moth there is a unique structure, 

 shaped like a sickle and used for the express purpose 

 of scraping up pollen from the yucca flower. Having 

 gathered a ball of pollen from the first yucca she visits, 

 the female moth flies to another flower of the same kind 

 and deposits her eggs amongst the unfertilised seeds. 

 Having done so, she deposits the pollen ball on the 

 stigma of the same flower, thereby ensuring that the 

 seeds will mature, and a very necessary operation this 

 is for both parties. 



Unless the seeds are fertilised the yucca cannot repro- 

 duce its kind there is nothing very wonderful in that, 

 half the plants the world over depend on insects for their 

 fertilisation, though, to be sure, the pollen is not usually 

 placed upon the stigma deliberately as in this case. The 

 fertilisation of the seed is equally important to the moth, 

 for upon the fertilised seeds the young larvae feed. 

 Fortunately each flower forms about two hundred seeds, 

 and luckily, too, the larvae develop quickly, only eating 

 about twenty seeds before turning into chrysalids, so that 

 both plant and insect are able to survive. 



" The whole proceeding is of great interest, showing 

 as it does the blind and instinctive nature of the organisms' 

 actions, and giving us an example of two species absolutely 

 dependent on each other for their continued existence. 

 If the moth had not the structure to form the pollen ball, 



