l82 The Irish NaUiralist. October, 
smaller island being frustrated by bad weather. In the 
present paper, I shall deal with my observations on the 
Flowering Plants and their alHes ; notes on the Mosses, 
Hepatics, Lichens and Marine Algae, as collected by Canon 
Lett or myself, follow. 
Assuming a tolerable completeness in Hart's Hst — an 
assumption justified by my own observations — considerable 
interest attaches to the study of the present-day flora on 
the following account : — At the time of his visit, and up 
till ten years ago, the island was inhabited. Some 80 acres 
were under tillage, and cattle and sheep grazed all over 
the higher rocky grounds at either end. At that time the 
extensive colonies of breeding sea-birds, for which the 
island has long been famous, were practically confined to 
the inaccessible slopes and cHffs. The Rabbits also, intro- 
duced at some bygone time, were kept in check by trapping. 
The withdrawal of man and of cattle ten years ago, has 
resulted in striking changes in the distribution of both 
animals and plants. The Puffins, Razorbills, and Guille- 
mots have moved up, and now occupy broad slopes and 
even flat ground formerly grazed. The Herring-Gulls, 
which have increased enormously in numbers, and the 
Lesser Black-backed Gulls, have occupied — one or other 
of them — nearly the whole of the two high ends of the 
island, including large areas of former pasture. Manx 
Shearwaters have even invaded the farm-land, and breed 
in holes in the earth and stone fences. The Bracken has 
swept in forests across the former grazing-lands occupying 
the two high ends of the island. At the same time, the 
spread of the vegetation has been much influenced by the 
fauna. The large area of former tillage which occupies 
the middle parts of the island has been completely invaded 
mainly by indigenous plants, but these are cropped down 
to the closest possible sward by the innumerable Rabbits. 
The birds control the vegetation inhabiting their vast 
colonies, beating out certain species, and permitting the 
growth only of those which can withstand the guano and 
continual trampHng. The facies of the flora has thus 
