26 



BROOKLYN BOTANIC GARDEN MEMOIRS 



to those that are full of them, and such early and late stages of develop- 

 ment should be accompanied by at least some transitional stages. 



A study of a good many of these kettleholes makes it seem probable 

 that just these conditions are to be found today. Why some have 

 been so delayed in their development as to show even at this late day 



Figure 4. Pool in kettlehole near Culloden Point. Note amount of water and 

 vegetation in it in September 1920, when this photograph was taken. In August, 191 8, 

 the water reached the edge of the kettlehole. See figure five for water-level in July, 192 1. 

 (Photograph by Harrington Moore.) 



only the initial stages of it, is not very clear. In those where there is too 

 much standing water, or where it does not recede early enough in the 

 season, there is practically pond or pond-side vegetation that may be found 

 over any part of Long Island. This is due to a too high and too steady 

 water-table. Many other low kettleholes, however, have no standing water, 

 and in practically all the cases where this has been observed the sides of 

 the kettlehole (the Downs) come down very steeply, suggesting at once 

 that material enough from these steep banks has filtered down to the bot- 

 tom. This would not, of course, change the level of the water-table, but it 

 would, and I think, has covered this over with silt a few inches deep in some 

 cases and perhaps a few feet in the largest and most steep-sided of them. 

 In contrast to this, the ponds that have been examined practically all have 

 shallow banks, and it may well be that the presence or absence of standing 



