Influence of ]\Iushrooms on Growth of Some Plants. 305 



bottom of the pot the tap roots growing into this fermenting substance 

 were killed and blackened at the tips. The leaves died back from the tips, 

 and the plants showed symptoms of severe injury. But as the fermenta- 

 tion was completed the plants gradually recovered, became healthy, grew 

 to some size, and the buckwheat, peas and beans flowered. Since the ex- 

 periment was a preliminary one to obtain suggestions for more accurate 

 work, the plants were watered with ordinary tap water which contained 

 certain mineral and possibly other substances available as plant food. 

 Notwithstanding this the plants which were supplied with mushrooms 

 for food made more growth than the checks. 



In the winter and spring of 1906 these experiments were repeated 



Fig. 117. — Corn seedlings growing in mushroom material. Photographed April 

 lyh. From left to right the material is as follows: First, distilled water; second, 

 not previously fermented musJiroom material: third, stronger concentration of pre- 

 viously fermenlrd mushroom material; fourth, weaker conccnlra'ion of previously 

 ferm-entcd mushroom material. 



under conditions of greater precision and better control, while at the same 

 time so arranged as to answer several of the phases of the problem as 

 outlined above. 



I. CULTURES WITH QUARTZ SAND AS SUBSTRATUM 



A rather coarse quartz sand was obtained by special order through a 

 local construction company. This was analyzed by Mr. Bizzel in the 

 .Chemical Division of the Experiment Station and was found to contain 

 20 



