FLORULA OF A PIECE OF WASTE GROUND AT ABERDEEN 233 



tunity of competing with one another in the struggle for 

 existence. 



I have been much interested in watching the results of 

 the struggle, noting the probable origin and fate of the 

 numerous casuals, and the increasing ascendency of certain 

 species and the consequent effects on the vegetation of the 

 area. The absence of various common species of plants 

 native in the Aberdeen district, or common weeds of culti- 

 vation here, is scarcely less striking than the prevalence of 

 others. In the hope that others may find interest in the 

 record, I summarise below an entire list of species observed, 

 stating in parallel columns their relative abundance or rarity 

 in each season. 



The scale I have used in my notes, reproduced here, 

 permits of somewhat greater accuracy than words, with 

 greater brevity. It is as follows : I scarce, 2 not rare, 

 3 common, 4 plentiful. Each of these is modified where 

 needed by the signs and + ; thus, while i means scarce, 

 i means very scarce, and I + means a score or so of 

 plants in the area. 2 means not rare, or one or two 

 examples in say five yards square ; 2 means say half as 

 many or fewer ; and 2 + denotes up to say twice as many. 

 3 denotes so common as to form a conspicuous proportion of 

 the flora, but only a minor part ; 3 - being up to say 

 5 per cent, and 3+ to about 25 per cent. 4 means 

 about half the vegetation by bulk, 4- that from one- 

 fourth to one-half, and 4 + that from about one-half to 

 almost the whole bulk of the vegetation consists of the plant 

 indicated. When only one or a very few individuals of any 

 species were noted, the actual number is stated in words. /. 

 denotes local ; v. I. denotes very local. 



The census was taken each year late in August or 

 early in September, and the condition of the species is noted 

 where that seems desirable ; veg. denoting the absence of 

 flowers or fruits, and/r. the presence of well developed or 

 nearly ripe fruits. Where not specially noted, the plants 

 were in flower and fruit at the period of observation. 



Notes on individual species follow the list. In all cases 

 in which I was in doubt as to any plant, I compared my 

 specimens with the specimens in the herbarium at Kew ; and 

 20 D 



