48 THE AMERICAN BOTANIST. 



knowledge of, and interest in, the trees. Upon application to 

 the Forestry Service, forms upon which the notes are to be 

 recorded will be sent, together with a pamphlet containing full 

 instructions for making the observations wanted. Those who 

 are alive to the value of a more intimate knowledge of the trees 

 should not neglect this opportunity to aid in the investigations. 

 Notes will be welcome from anyone interested in the subject. 



Colorless Plants. — So universally distributed is plant 

 green, or chlorophyll, that when we chance upon a plant which 

 lacks this color it is always an object of wonder. To those 

 who have studied the physiology of plants the wonder is in- 

 creased for it is a well-known fact that the plant food is made 

 in the leaves and stems of plants and that the energy for mak- 

 ing this food is derived from the sunlight by the chlorophyll. 

 Without chlorophyll, therefore, the plant can make no food 

 for itself. There remains but one method of existence open 

 to such plants, namely, to depend upon some other plant or ani- 

 mal for sustenance. The dodder solves the problem by boldly 

 attaching itself to some green plant and by means of special 

 sucking organs, called haustoria, taking from it the needed 

 food. Other plants have formed partnerships with bacteria 

 and fungi, in which the latter obtain for them the food they 

 cannot make for themselves. Curiously enough many of the 

 plants which long ago gave up an independent existence still 

 bear indications about them of a higher state, for the leaves, 

 though no longer functional are found to have retained the 

 stomata, or openings, which in higher plants, admit the air to 

 the interior of the leaf in the process of food-making. 



