The Ancestry of the Cypress. 43 



The remains of one of these Pleistocene swamps has been laid 

 bare by the recent erosion of the Ra])pahannock river a short 

 distance above the town of Tappahannock, Virginia. The peat 

 which represents the old swamp is exposed for a thickness of 

 four or five feet and is overlain by from fifteen to twenty feet of 

 sand and clay. It contains the remains of other members of 

 the Pleistocene biota in addition to the Cypress, although the 

 latter constitutes the dominant element. Sometimes recogniz- 

 able leaves are found but usually seeds or fruits furnish the only 

 clue to the identity of the plants associated with the Pleistocene 

 Cypress. At this locality hickory nuts, beech nuts, grape and 

 gum seeds have been collected. Associated with the plant re- 

 mains are fragments of the elytra of beetles, occasional insect 

 galls and infrequent molluscan shells. Another Pleistocene 

 Cypress swamp is shown in Fig. 2. This is also along the Rappa- 

 hannock river in Virginia, and is introduced to show the sharp 

 line which separates the old swamp deposit from the overlying 

 sand and gravel. The Cypress roots and stumps recall forcibly 

 those of their recent allies and should be compared with the many 

 reproductions which have been published of the zone of weath- 

 ered Cypress butts lining the shores of Lake Drummond in the 

 Dismal Swamp. Evidently this region was a sinking one at the 

 time this Pleistocene Cypress swamp flourished, for we can see 

 the progress of events as though the record were a written one; 

 how the estuary waters advanced over the swamp, inhibiting 

 the growth of the seedlings and hr w the old trees gradually 

 wasted and fell, the waves slowly scouring the surface and de- 

 positing their coarse sediments layer upon layer as the land con- 

 tinued to subside. With the final recession of the last ice sheet 

 we find evidence of somewhat warmer climatic conditions than 

 prevail today. This is shown by various subfossil animals and 

 plants collected at certain points from Maryland to ^Massachu- 

 setts as well as by the isolated occurrence of various members 

 or our existing flora many miles to the northward of their normal 

 range. An example of this sort has recently been recorded by 

 Sears in Essex County, Massachusetts. In the Pleistocene 

 records of the Cypress collected by the writer there are five 

 localities north of the present range of the species, that in New 

 Jersey being nearly 150 miles north of the present northern 

 limit. That these facts have more than a local significance is 



