300 Froceedingn Port. Soe. Nat. Hist. 



Long Island and in southeastern Xew England; and more 

 recently Fernald' has demonstrated their occurrence in l^ew- 

 foundland. The arguments for this are too well known to 

 need discussion here. Suffice it to say that there is good 

 evidence of a land connection directly after the Glacial 

 Period, which reached from iSTew Jersey to Cape Cod and 

 thence to Newfoundland and along which the coastal plain 

 plants were able to migrate northward. This Carolinian ele- 

 ment may have gone northward for the first time at the close 

 of the Glacial Period, but in all probability it existed in the 

 Xorth previous to this period and was driven south by the 

 ice into Xew Jersey where it remained until the retreat of the 

 glacier and then returned over the land-bridge. This land- 

 bridge has noY/ been submerged or broken up and only iso- 

 lated fraginents remain, each of which has a typical coastal 

 plain flora. 



Although this explanation holds good for the presence 

 of Carolinian species in Newfoundland and southeastern 

 Xew England it does not explain the occurrence of such 

 forms as Corema Conradii and Iludsonia ericoides on the 

 rocky granite summits of the Penobscot Bay islands. Be- 

 tween the land connection above referred to and the cen- 

 tral portion of The Maine coast there existed in early 

 post-glacial times, as at present, a deep and wide expanse of 

 water, the Gulf of ]\raine. This must have been an effectual 

 barrier to prevent any of the coastal plain species from reach- 

 ing Maine by the land bridge. The only other route for 

 these plants was across the glaciated areas of southern Xew 

 England. We have already noted that the glacial till which 

 covered this region was a mixed soil containing a great va- 

 riety of food elements. For plants which could exercise a 



1. Fernald. A Botanical Expedition to Newfoundland and South- 

 ern Labrador. Rhodora 13: 109-163 (1911). 



