Dec. 1901.] BOTANICAL SOCIETY OF EDINBURGH 125 



mid June there is a rush of plants into flowering. In 

 autumn, the flowering tails out until, in October, frosts and 

 the first fall of snow close the season ; the flowering 

 periods that the frosts cut short are not of alpine but of 

 lowland plants, and in a large measure of such weeds 

 of fields and roadsides as owe their presence to man. 

 Milton of Clova more than fifty years ago was a village 

 of handloom weavers, who have now disappeared. H. C. 

 Watson visited Clova in 1844 when, according to his 

 manuscripts and herbarium now at Kew, he found more 

 of the class of plants which are dependent on man than 

 we have seen. 



The strath of the Deeside, at Braemar, carries plants to 

 higher levels than at Clova, so too the strath of Glen 

 Muick ; with this fact we are not further concerned than 

 to remark that only in the straths of these glens is to be 

 found the soil which encourages these plants to grow. 

 The experience of the cultivator of Clova tells him that 

 immediately he leaves the dried-up lake-beds of the valley, 

 he finds only peat and stones. 



Next, a word on the warmth of some of the glens. It 

 is well known how valleys, running east and west, unless 

 open to the winds, gather in summer a considerable amount 

 of heat ; such is especially the case with Glen Fiadh, 

 where, on cliffs facing south, many of the plants we have 

 observed reach their greatest elevation. 



And lastly, it is not hard to see that where protection 

 from the wind ceases, and the hillsides pass over into the 

 moors, the flora changes in biological character more than 

 at any other point. Here annuals disappear, classes Po 

 and F almost disappear, and anemophilous flowers suddenly 

 advance to forty per cent, of the zonal flora (they are 

 31-55 below 1000 feet, 31-98 between 1000 and 1500 

 feet, 32-78 between 1500 and 2000, and 31-19 between 

 2000 and 2500 feet). These changes are accompanied 

 by a change in appearance of the vegetation evident to the 

 eye, and make the 2500 feet contour line one of importance 

 to us in considering the fertilisation of Clova flowers. 



