POLLEN AND SPORES — LEOPOLD AND SCOTT 319 



somewhat rich in calcium. The basin is no longer a lake, for peat has 

 filled the depression to create a bog in which the peaty muck at the 

 surface is rich in humic acids and low in minerals. Hardwoods rather 

 than spruce now grow around Totoket bog. Hence it is clear that 

 the old muds underlying the peaty surface of the bog contain a record 

 of a climatic and aquatic environment strikingly different from mod- 

 ern conditions in the Totoket basin. 



An outstanding example of the use of fossil pollen, along with 

 fruits, seeds, and wood, in a broad approach to the reconstruction of 

 a Tertiary (upper Oligocene) environment is the investigation of the 

 Brandon lignite. This unusual deposit of brown coal, near Brandon, 

 Vt., was first discovered about 100 years ago and served as the fuel 

 source for an iron industry once the largest in the United States. 

 Recent rediscovery and study of the lignite (macrofossils : Barghoorn, 

 1950 ; microfossils : Traverse, 1955) has resulted in the identification of 

 more than 50 genera of flowering plants; about 60 percent of these 

 are represented by pollen alone. 



The affinities of the plants from the Brandon lignite reveal that 

 ecologically they form a subtropical assemblage which probably grew 

 under conditions much like those in the river swamps of the Atlantic- 

 Gulf Coastal Plain. Such significant genera as Liquidambar (sweet 

 gum), Nyssa (tupelo), Oyrilla, Gordonia, and Engelhardtia, now 

 found only in much milder climate than that prevailing in Vermont, 

 are represented by fossil pollen. In addition, presence in the flora of 

 some genera now growing under warm conditions but only in south- 

 east Asia, e. g., Glyptostrobus and Alangium, is proved by the occur- 

 rence of their pollen. The present ecology of these and the other 

 Brandon genera is compelling evidence for the existence in Vermont 

 in the early Tertiary of climatic conditions similar to those now typi- 

 cal for coastal Florida or South Carolina. 



Pollen from the Tertiary brown coals in Europe has been inten- 

 sively investigated (Thomson, 1953), but the known Tertiary vege- 

 tational history of the United States is as yet based primarily upon 

 leaves and other macrofossils. From studies such as that of the Bran- 

 don lignite, it is clear that palynology can contribute to a fuller under- 

 standing of the evolutionary and migrational history of past and 

 present vegetation by adding another category to the list of detached 

 fragments from which the geologic record of plants must be deduced. 

 The potential of pollen and spores in this respect arises not only from 

 their occurrence in rocks that do not contain other plant parts, but 

 also from the fact that a single slide may contain the pollen of 20 

 or more genera ; a sample of this size is amassed much more tediously 

 when dealing with plant macrofossils. 



