234 THE PLANT WORLD 



age, that when they iirst apeared they were probably white, 

 and that subsequently none of them turned green. The im- 

 mediate cause for the formation of suckers in the redwood is 

 considered by Peirce to be conditions unlike those usually 

 prevailing among the redwoods, as felling, injury of any 

 sort abo\'e or below ground, or other considerable dis- 

 turbance. It is suggested that the white suckers may be the 

 result, not of too little light, but of insufficient warmth for 

 the formation of chlorophyl pigment or chromatophores. 

 When once the shoot appears devoid of the customary green 

 color it remains white, so long as it retains its connection with 

 the mother trunk. In fact, it is a parasite in which the phloem 

 and the xylem of host and parasite are continuous. If, 

 how^e\'er, the connection with the source of its food supply is 

 cut oft so that the need arises for self support, it may have 

 the power to turn green, at least in part. If this is the case 

 It seems probable that, if severed from their food supply, the 

 suckers might as a result of the stimulus of the food re- 

 quirement turn green, even should the temperature remain too 

 low for them to do so when the stimulus is absent. 

 Carmel-by-the-Sea, California. 



VITAL TENACITY OF AN ORANGE TREE 



STUMP. 



By Charles F. Saunders. 



The house in which I reside in Pasadena, California, 

 was built just three years ago, on land which was formerly 

 part of an orange gro\'e. In making room for the house 

 a few orange trees were cut down — on what exact date I do 

 not know — but certainly over three years ago. No cellar 

 was dug, but stone foundations two feet high were built, upon 

 which the floor of the house was laid, making a large air- 

 chamber of the aforesaid height beneath the house. This 

 chamber is dark save for a modicum of light which enters by 

 two small cellar windows, and no drop of rain or other water 

 whatever has moistened the ground of this subdomal en- 



