Environment and Adaptation 211 



who have investigated this phenomenon, have 

 pointed out that the failure to develop the normal 

 color in the flower may be attributed, not directly 

 to the chemical effect of the light, but to the ex- 

 haustion of formative materials due to rapid growth 

 incited by the high temperature. The photosyn- 

 thetic activity, owing to the weakness of the illumi- 

 nation, is not sufficient to provide the extra material 

 needed for the development of the normal pigment 

 in the flowers, but this is used up in the growth of 

 the plant. If the same plants are grown where it 

 is cooler, and growth therefore less active, while 

 the illumination is equally strong, pigment will re- 

 appear in the flowers. The light, therefore, does 

 not directly cause the production of the pigment, 

 but, by promoting photosynthesis, allows for the ac- 

 cumulation of the substances necessary for the de- 

 velopment of the pigment. 



FUNGI 



Fungi Either Parasites or Saprophytes. What- 

 ever may have been the origin of the Fungi, they 

 differ radically, both in their structure and habits, 

 from the green plants, and show many unmistakable 

 instances of special adaptations. They subsist 

 largely upon solid organic matter, such as the liv- 

 ing bodies of plants and animals, or dead substances 

 like decayed wood and vegetable mold. The plant 

 body consists of fine filaments, or hyphae, which by 



