296 



Formation and Flora of a Shingle Island, 



[Sess. 



low-lying fields close by ; this has been known to happen 

 several times in one month, but such high floods do not occur 

 every year. 



The following tables give some idea of the annual rain- 

 fall and temperature of the district : exact figures were not 

 available, and we drew up these tables ourselves from maps 

 in the 'Journal of the Scottish Meteorological Society.' The 

 rainfall maps are in the Third Series, No. X., and the 

 temperature maps in Third Series, Nos. XIII. and XIV. We 

 had some difficulty in estimating the rainfall figures. 



Rainfall (1866-90). 



(Dalmally is just on the line between the 60-80 area and that above 80.) 



Mean temperature (1856-95). 



January . 



February 



March . 



April 



May 



June 



under 40 



under 40 



under 40 



40-45 



50-55 



55-60 



July . 



August 



September 



October 



November 



December 



. 55-60 

 . 55-60 

 . 50-55 

 . 45-50 

 . 40-45 

 under 40 



Mean annual temperature 45-50. 



On 15th Sept. 1906, we saw the island half submerged 

 after ten days' heavy rain (see Map III., where the light parts 

 correspond to what was showing above the water) ; and on 

 17th Sept., when the water had subsided, we examined the 

 flood-drift carefully, in order to see what bearing it had on 

 the flora of the island. The following is the list of our 

 finds : — 



Leaves. — Sycamore, bird-cherry, rowan, ash, birch, alder, oak. 



Twigs. — Raspberry, bramble, heather (Calluna), ash, alder, 

 oak, willow, larch; the alder predominating. Nearly all 

 these twigs, however, were old and dead, and none seemed 

 capable of growing. There were probably twigs of other 

 trees, too, but we found them hard to identify. 



