40 GUERMNSE Y. 
will show that the flowering-plants, ferns, and fern-allies are divided 
as follows :— 
Natives... “se “ Br eed Se 588 
Colonists ¥e me ae a sat 52 
Denizens ae “ Sig Me 5 23 27 
667 
Aliens 4a me bes 56 
Casuals are oi Ps 64 
Extinct er my ce 22 
— 142 
Total ..s =a 3 809g speciés. 
Although the flora of Guernsey appears at first sight numerically 
large for so small an island, it probably does not exceed the average 
when all the circumstances of geographical position are taken into 
account. It must be remembered that the smaller the area the 
larger will be the flora relatively to the space, in all places presenting 
somewhat similar features. This relation of species to area has 
been admirably illustrated by Watson in the fourth volume of his. 
great work, the Cylele Britannica, where he shows that a single 
square mile of diversified country in the north of Surrey produces 
nearly one-half of the wild plants found in the entire county, which 
has an area of 760 square miles. The whole of Britain, he cal- 
culated, only furnishes an average of one species to every sixty-one 
square miles of area. 
At the time tne Cyde/e Britannica was written, or rather the 
Compendium, in 1872, which expresses the author’s later views, the 
number of plants admitted as British was reckoned at 1425 These 
were classified by Watson under certain ‘types of distribution,’ which 
he defines as follows :— 
1. British type: species widely spread throughout Britain. 
2. English type: species chiefly seen in south or south-middle 
Britain. 
3. Scottish type: chiefly seen in north or north-middle Britain. 
Intermediate type: chiefly seen in middle Britain. 
Highland type: chiefly seen about the mountains. 
Germanic type: chiefly seen in east England. 
Atlantic type: chiefly seen in west England. 
Local species: restricted to single or few provinces. 
After excluding the Rubi, the Characeae, and a number of 
Aliens, Casuals, and segregates not classified by Watson, besides the 
seventeen non-British plants, it will be found that Guernsey possesses 
636 out of these 1425 species. Although it is parva componere 
Oe 
