3o6 



Bulletin 240. 



less than one-tenth of one per cent organic matter and less than one-tenth 

 of one per cent mineral matter, the latter being mostly an iron substance. 

 Wire culture baskets nineteen and one-half cm. deep by twelve cm. in 

 diameter were employed, and after being filled with sand were paraffined 

 according to the method employed by the Bureau of Soils of the U. S. 

 Dept. Agr.* 



The mushrooms were grown in the basement and in the greenhouse. 

 They were first dried and then powdered. Some of this material was 

 used fresh, i. e., it was placed in the crates of sand in an unfermented 

 condition, while other material was allowed to ferment in distilled water 



Fig. 118. — Corn seedlings growing in mushroom material. PJiotographcd May yJi. 

 From left to right the material ts as follows: First, distilled water; second, not pre- 

 viously fermented mushroom material; third, stronger concentration of previously 

 fermented mushroom material; fourth, weaker concentration of previously fermented 

 mushroom material. 



before using at the rate of two grams dried mushrooms to two hundred 

 cc. distilled water and a weaker concentration at the rate of two-thirds 

 gram powdered dry mushroom in two hundred cc. distilled water. There 

 were thirty-six baskets with ingredients of the foregoing as follows: 



Numbers 1-14 contained two grams jiowdered dry unfermented 

 mushroom in the bottom third of each basket. 



Numbers 15-23, jHirc sand as check. 



* Circular No. 18, Bureau of Soils, U. S. Dept. Agr., 1-6, 1905. 



