KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 50. N:0 3. 73 



was warmer than it is now. A sample of the clay, in whicli the trunks and twigs are 

 embedded, contained an abundance of pollen-grains of two or three conifers, spores of 

 two pteridophytes and one pollen-grain of a dicotyledoneous plant. It may of course 

 seem stränge that nothing like this forest-bed has been found in any other place, but 

 perhaps it is stranger, that anything at all has been left to bear witness of a time 

 when the Falklands were, at least to some extent, forest-clad, and that the preserva- 

 tion of the treetrunks in Westpoint Island is due to a concatenation of favourable 

 circnmstances. I do not think we can imagine that the deterioration of the climate at 

 the end of the Tertiary came on very siiddenly, but that the forests died and most of the 

 trunks decayed before the solifluction had really set in. Of course we know nothing of 

 the former extension in the islands of those coniferous forests, nor if they were pure 

 or mixed with leaf-trees. I should guess that the higher parts of the mountains and 

 the slopes exposed to the wind bore heaths or meadows of the same general stamp 

 as the present one, but also that quite a number of plants, that have disappeared 

 for ever, formed the undergrowth in the forests. In this connection I ought perhaps 

 to say a few words on group 2 A. One might easily be led to assume that they 

 were preglacial relics from a warmer time when forests existed in the islands, for 

 nearly all of them — except Ranunculus acaulis — are forest plants, and Adianium 

 chilense, Blechnum magellanicum and Polyslichuin adiantijorine are often found growing 

 in Libocedrus-iorests, as are also species of Asnrca. The ferns are also frequent in 

 the south Chilean rain-forest, but do not reach the colder parts of it in West Pata- 

 gonia or Fuegia; they are very local in the Falkland Islands and show traces of 

 their struggle against unfavourable climatic conditions, Thus one wouki certainly 

 expect, that such delicate plants would disappear first of all and not be able to 

 survive the solifluctional period. On the other hand, the high andine elements of 

 group 2 B, Carex vallis pulchrce and Draha jalklayidica may very well have survived 

 without sustaining damage. No very great change in the climate is required to call 

 forth a detritus-flovv; a slightly lower temperature, an accumulation of snow in the 

 winter, in summer a melting process making the soil saturated with water during 

 day time and frozen at night, and perhaps a greater rainfall, and we should see the 

 process repeated. Besides, solifluction is still going on even if on a very small 

 scale (see J. G. Andersson's paper, p. 23). 



To judge from the commonness of stone-runs and of fossil flowing-soil, the 

 areas covered by the detritus-masses must have been very considerable. But one 

 may be pretty sure that they did not cover the whole of the islands, but that there 

 were patches of vegetation in many places, both on the hills and near the coast. 

 J. G. Andersson thinks that the conditions were mucht he same as they are on Bear 

 Island (Beeren Eiland) to-day, and if this be true, we have no reason to suppose 

 that the Falklands were destitute of vegetation. Below, I have indicated the im- 

 portant fact that Lafonia was not covered by the detritus-flow, thus forming an 

 oasis of considerable extent. During our ride along and amid the Andes from Lake 

 Nahuelhuapi to Punta Arenas we frequently met with the process of solifluction 

 going on at higher altitudes (1,000 m. and more). It was of great interest to study 



K. Sv. Vet. Akad. Handl. Band 50. N:o 3. 10 



