NEW CREATIONS IN PLANT LIFE 



severe. At first they accomplished this by 

 dropping all of their leaves, thus preventing too 

 much evaporation, while the fat, smooth stems 

 were left to perform the functions of the 

 leaves. The opuntias to this day always shoot 

 out numerous rudimentary leaves, which per- 

 sist a few days or weeks and then, having no 

 function to perform, drop off. 



"But the opuntia had yet to meet another 

 enemy. Desert animals were hungry for their 

 rich stores of nutriment and water, so the 

 rudimentary leaves were replaced by awful, 

 needle-like thorns, placed at exactly the right 

 angles for defence and, at the base of these, 

 partially imbedded in the stems (now leaves) 

 were numerous bundles of smaller needles, 

 more than ten thousand to each leaf. These 

 are even more dangerous than the larger nee- 

 dles, producing great pain, inflammation, and 

 at last death, to animals which were pressed 

 by starvation to consume them for food. 



"The opuntias having once been thornless, 

 there was no reason why they should not again 

 revert to a state of partial thornlessness, and 

 this is precisely what they do. In the Ha- 

 waiian Islands a partially thornless opuntia is 



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