332 



GEORGE HARRISON SHULL 



2 dm. deep with soil taken from the pond-bed. The jar was filled 

 with ordinary tap water which was replenished from time to time 

 as it evaporated. The jar was wrapped in several thicknesses of 

 brown paper, and the top covered with a piece of wire gauze. 

 It was placed in an unused room on the second floor of the 

 Laboratory where it was kept relatively cool, though rarely 





Fig. 1. The bed of St. John's Pond, at Cold Spring Harbor, Long Ishmd, five, 

 iind one-half months after the breaking of the dam. Photographed by Forrest 

 Shreve, July, 1904. 



cold enough to freeze a little, and moderately lighted, throughout 

 the ensuing winter. 



The following species supplied the seeds involved in this experi- 

 ment, and as the soil had not been sterilized, other species whose 

 seeds had been in the mud of the pond-bed were doubtless also 

 included. 



