A FEW NATIVE ORCHIDS 223 



variation in all organic life being an essential and 

 amply demonstrated postulate of the entire theory 

 of natural selection. Let us suppose a flower 

 whose nectary chances to be only six inches in 

 length. The moth visits this flower, but the tip 

 of its tongue reaches the nectar long before it 

 can bring its head into the opening of the tube. 

 This being a vital condition, the moth fails to 

 withdraw the pollen ; and inasmuch as the pol- 

 len is usually deposited close to the head of the 

 moth, this flower would receive no pollen upon 

 its stigma. This particular blossom would thus 

 be both barren and sterile. None of its pollen 

 would be carried to other stigmas, nor would it 

 set a seed to perpetuate by inheritance its shorter 

 nectary. 



Again, let us suppose the variation of an extra 

 long nectary, and the writer recently saw a num- 

 ber of these orchids with nectaries thirteen inches 

 in length. The moth comes, and now must needs 

 insert its head to the utmost into the opening of 

 the flower. This would insure its fertilization 

 by the pollen on the insect's tongue ; and even 

 though the sipper failed to reach the nectar, the 

 pollen would be withdrawn upon the tongue, to 

 be carried to other flowers, which might thus be 

 expected to inherit from the paternal side the ter^- 



