18 Harrell — Movements of the Strand Line 



Brunswick, Prince Edward Island, and the Magdalen Islands, we 

 find many such species, some identical with, others different from 

 those reaching Newfoundland, and on Sahle Island there are some 

 similar cases, some of the species from the south getting to Sable 

 Island but not to the other areas. Now it is inconceivable that 

 these southern types should have extended to these remote out- 

 lying areas under conditions much colder than at jDresent, and 

 judging from their present very restricted occurrence in these 

 northern regions it looks as if they must have reached them dur- 

 ing a period somewhat warmer than at present. They either 

 migrated northward on the continental shelf prior to the Wis- 

 consin glaciation and persisted outside the subsequently glaciated 

 area, finally taking possession of their present isolated habitats on 

 the receding of the ice or, as seems to me perhaps equally prob- 

 able, the continental shelf, including the present southwestern 

 half of the Gulf of St. Lawrence, must have been considerably 

 elevated after the Wisconsin, long enough for the migration — 

 including some mammals, and even fresh water and land snails. 



The question is complicated by a mass of evidence not yet 

 published upon : briefly that in the regions above enumerated, 

 there is also a remarkable proportion of the flora, quite unknown 

 elsewhere in North America, which is strictly identical with the 

 flora of the Atlantic area of Europe, even including the Azores. 

 We have startling cases (several scores of them) of species 

 strictly indigenous in Newfoundland and known otherwise only 

 in the region from the North Sea to Portugal, or to western 

 France, and in some cases also on the Azores or even Madeira. 

 Similar and very striking cases have come to light on Sable Island, 

 the Magdalens, Prince Edward Island and eastern New Bruns- 

 wick, indicating pretty clearly a large flora (and snail fauna, too) 

 which must have crossed on the mid-Tertiary land and been 

 stranded at the present margins of the Atlantic. Now these 

 cases imply some tract along the coast, especially of Acadia, and 

 Newfoundland, which held this flora and fauna continuously 

 through the Pleistocene. ........ 



Another point : in a few cases plants clearly indigenous on these 

 isolated areas, Newfoundland, Sable Island, Prince Edward 

 Island, etc., are species identical with, or representative of, the 

 Australasian flora, and seem to be harking back to the Eocene. 

 So you see, that it is not very easy to give an offhand brief 

 answer to your inquiry about the botanical evidence. My 

 students, Messrs. St. John and Blake, and I are wading aboutin a 

 flood of such evidence, trying to work out the exact identities and 

 affinities and come to safe anchorage, but it is a vast problem and 

 every species has to be studied intensively, often requiring a com- 

 plete monographic study of a world-wide group before we are 

 sure of our ground. 



It will be a long time before we are able to publish our detailed 

 results. If you wish to use the above as a preliminary statement 

 you may do so. 



