48 SAVAGE SURVIVALS 



horns would naturally be; these are sometimes 

 shed and grow again. 



In many plants the petals and other parts of the 

 flower are rudimentary. The purpose of the pet- 

 als is to advertise the flower to insects by bright 

 displays of color. In some flowers this is done by 

 the stamens, while in others (the poinsettia, for in- 

 stance) this advertising business has been taken 

 over by the leaves adjacent to the flower. In the 

 dandelion all of the outer florets have vestigial 

 pistils. In some varieties of the cultivated gourd, 

 wliich no longer lead the climbing life, the tendrils 

 are rudimentary. 



Parasitic animals and plants are commonly 

 much degenerated, having abandoned entirely 

 many of the organs which they had when they led 

 a free and independent existence. Such organisms 

 are, as a result, nearly always rich in ruins. The 

 narwhal is a kind of whale that lives in the far 

 north. It has only two teeth. They grow straight 

 out in front. One of them grows to be six or eight 

 feet long and is used in spearing its enemies and 

 in breaking holes in the ice. The other one is ves- 

 tigial, never projecting beyond the skull. In the 

 pouched mice of Australia, the young are no 

 longer carried in the pouch and the pouch has 

 degenerated to a mere fold of skin on the abdo- 

 men. 



The so-called '* wisdom teeth" in man are teeth 

 which are in the act of passing out of existence. 

 They appear late in life and in many persons do 



