118 TORREYA 



tainly the grain size is within the range (50-104 microns) given by Wode- 

 house (1935) for Abies balsamea and its mean (83.6) is close to those deter- 

 mined for these two species {A. balsamea 78.2, A. fraseri 79.8) by Cain 

 (1944a). As for the pine the size frequency curve strikingly resembles that 

 obtained by Cain (1944b) for fossil pine pollen from buried soils in South 

 Carolina with one exception. The mode at 62.4 microns is missing. The other 

 two peaks in the curve are the same in position and relative height. Cain con- 

 cluded that the mode at 46.8 microns indicated the presence of Pinus banksiana 

 Lamb, and that the mode at 54.6 indicated the presence of Pinus glabra Walt. 



It is therefore reasonable to presume that the ancient lake Jerome was sur- 

 rounded by a forest of jack pine on the surrounding coarse, sandy ridge. 

 Beyond on the sand plain to the west was an extensive mesic forest with oak 

 and fir predominating. It suggests a situation very similar to that existing as 

 far north as northern Minnesota or New England where the northern conifer 

 forest and the hardwood forest meet (Buell and Gordon, 1945). It may not, 

 however, represent such a transition zone since Potzger found a similar mixed 

 flora in bogs of the unglaciated part of New Jersey (Potzger, 1944). It is 

 difficult to fit Pinus glabra as we know it today in this picture. It now occupies 

 forests of the low, warm humid coastal region south of North Carolina. 



There is no doubt that this forest should be referred to Wisconsin time. 

 The pollen spectrum of the overlying peat is continuous to the present. Though 

 the author's data are not completely worked out yet there is no indication of a 

 severe cold period occurring since the abrupt disappearance of Abies above 

 its maximum here described. 



North Carolina State College 

 Raleigh, North Carolina 



Literature Cited 



Buell, Murray F. & Wm. E. Gordon. 1945. Hardwood-Conifer forest contact zone in 

 Itasca Park, Minnesota. Am. Midi. Nat. 34: 433-439. 



Cain, Stanley A. 1940. The identification of species in fossil pollen of Pinus by size- 

 frequency determinations. Am. Jour. Bot. 27: 301-308. 



1944a. Size-frequency characteristics of Abies fraseri pollen as influenced by 



different methods of preparation. Am. Midi. Nat. 31 : 232-236. 



1944b. Pollen analysis of some buried soils, Spartanburg County, South Carolina. 



Bull. Torrey Club 71: 11-22. 

 Potzger, John E. 1944. Investigations of sediments from nine bogs within the pine barrens 



of New Jersey. Am. Jour. Bot. 31: 7s (abstract). 

 Wells, B. W. & I. V. Shunk. 1931. The vegetation and habitat factors of the coarser 



sands of the North Carolina coastal plain : An ecological study. Ecol. Monographs 



1: 465-520. 

 Wodehouse, R. P. 1935. Pollen grains. McGraw Hill, N. Y. 



