116 



of other mixtures of gases than air and this is very easily accom- 

 plished by simply connecting the receiving end of the apparatus 

 in the beginning, not at once with the mercury reservoir, but with 

 a gas tank or generator of the gas desired. After a current has 

 been run through the apparatus long enough to ensure the com- 

 plete replacement of air, the apparatus may then be connected 

 with the mercury supply as before. 



There are many operations to which this apparatus is appli- 

 cable. 



Barnard College, Columbia University. 



HEXALECTRIS APHYLLUS, A TRUE SAPROPHYTE 



By Winifred J. Robinson 



The New York Botanical Garden recently received from Mr. 

 R. M. Harper, living specimens of Hexalectris aphyllus, collected 

 at Cuthbert, Ga., July 17, 1903, which have unusual interest, 

 from their unique saprophytic character. 



The term saprophyte has been applied to plants in all stages 

 of dependence upon organic substances for food, since the time 

 when Aristotle formulated his comprehensive class of humus 

 plants. Pfeffer * says : " Plants which are unable to assimilate 

 carbon dioxide must obtain all their organic food materials from 

 without (heterotrophic or allotrophic nutrition) ; by others a 

 portion only of their organic food is obtained from the external 

 world, the rest being supplied by the imperfectly developed 

 chlorophyl apparatus (mixotrophic plants)." Green (Intr. to 

 Veg. Phys., 198) states that "the characteristic feature of sapro- 

 phytes is that they derive at least a part of their food from 

 decaying animal or vegetable matter, absorbing it in some cases 

 as actual food-stuffs, and in others as organic compounds which 

 require relatively little expenditure of energy to build them up 

 into proteids or carbohydrates." MacDougal f takes into ac- 

 count the nutritive unions formed with mycorhizas and bacterial 



* Phys. of Plants, translated by Ewart, i : 363. 1899. 



f Symbiosis and Saprophytism. Bull. Torrey Club, 26 : 5 11 - 1 899. 



