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Figure 1. Gametophytes of Equisetum arvense. A large one, about 6 milli- 

 meters in diameter, is indicated with a white arrow ; a smaller one beside it, 

 dark in the photograph, is similarly indicated. Young sporophytes are also 

 visible in the photograph. 5/6. Figure 2. Gametophytes of E. arvense of vary- 

 ing sizes, appearing as dark spots on the soil, some hardly visible, some several 

 millimeters in diameter. 2/5. Figure 3. Young sporophytes of E. arvense, the 

 gametophytes from which they originated visible at the base of some. 1/3. 

 Figure 4. Gametophyte of E. arvense, in the white circle, bearing two sporo- 

 phytes, each of which shows a primary and a secondary shoot. 5/6. 



clearly and sharply delimited, and above this the steep slopes were 

 completely occupied by plants. On the sides and bottom of the exca- 

 vation, below the erstwhile water level, stood the gaunt remains of 

 trees and shrubs that had been submerged, some presumably for 

 two decades. At the former water level was a hydrosere, with cat- 

 tails, sedges, alders, willows, etc., though the water was gone. 

 Slightly above this former water level, mature sporophytes of 

 Equisetum arvense were found growing in considerable abundance. 

 Although strobili in this particular locality have not been studied, 



