123 



killing all forms that have obtained a foothold, and the struggle must begin 

 all over. Such a storm s\vej)t the Miohilliu'la beach for almost a week during 

 the past suunner, blotting out absolutely the middle beach fiora. In a week, 

 however, the brave plants began to show themselves again and to renew 

 the apparently hopeless struggle. The most notable member of this flora 

 was the succulent leaved crucifer, cakile ciJviittila (Bigel.) Hook. The 

 adaptation in this case is plainly against the dessicating action of wind and 

 sun. The plant also is able to withstand, to a certain extent at least, a 

 sand covering of considerable thickness, forcing its way through it to the 

 surface apparently but little injured by its temporary burial. Its stubborn 

 erectness and unyielding rigidity are characters "that at once serve to dis- 

 tinguish it from the other me]ubers of this flora. 



More numerous uiion this stretch of beach is Cnphorhm polygonifolia L. 

 This j)rostrate spurge finds its protection in its close hugging of the sands 

 which are here always damp at a slight depth, whatever may be the sun's 

 heat. A covering of sand does not seem to kill it, unless it is several inches 

 thick, new shoots emerging fi*om the crown, finding their way to the surface 

 in a few days. In spite of these two species, the nnddle beach strikes one 

 as practically destitute of plants — and the wonder grows as the conditions 

 are studied that the few that do occur have found even a temporary lodg- 

 ment. 



The upper beach and the active dune region present a much more varied 

 and consequently much more interesting flora. The opposing forces here 

 are the fierce rays of the sun, the almost constant winds and the shifting 

 sands. In high winds the mechanical action of the sands is very great, 

 often completely destroying well-established plants. These factors have led 

 to the development of the most pronounced xerophytic characters found in 

 this latitude, and this in spite of the fact that there is no scarcity of water 

 in the soil. Even after the long summer drought, the sand is moist at a 

 slight distance below the surface. The most marked adaptations in this 

 region are those against the <!overing of the plant with sand, exposure of 

 roots by the shifting of the sand, excessive evaporation because of sun and 

 wind, and the mechanical action of the sand driven by storms. Practically 

 eveiy device against these destructive agencies is here in evidence. They 

 are so well known that they need not be recited in this connection. 



Most interesting, perhaps, are the provisions against submergence by 

 the sands. In the case of the po])lars, willows and dogwoods, the sprouting 

 habit in connection with the habit of sending out roots from any node in 



