154 The hhh Naturalist. August, 



DeforcstatiojL or Plantation. — See remarks under "Climate." 

 Ireland, \Yhich was once extensively wooded, has been largely 

 deforested, but data are lacking as to statistics of plants more 

 than a century ago. 



Smoke. — Only in the north, north-east, and east — e.g., near 

 towns of Dublin, Belfast, Cork (in S.), and counties of Dublin 

 and Wicklow especially — has smoke been the cause of 

 extinction. 



Building Operations, ^e. — In Limerick Asplenium viayijium, 

 and in Dublin and Wicklow many mosses and hepatics have 

 been exterminated by building or removal of mud walls, and 

 in Sligo by demolishing of thatched roofs. 



Hawking. — \\\ Kerry (N. and S.) and Co. Cork Trichonianes 

 radicans, and in Co. Down Osmunda regalis have been more 

 or less exterminated by professional hawkers. 



Collecting. — In S. Kerry various mosses and hepatics; in Cork 

 Hookeiia Icetevireyis ', in Clare Adiajituni Capillus-veneris, in 

 Sligo Osimmda regalis, in x^ntrim Aspleniuvi viarinuui and 

 in Co. Down many plants have become extinct or dimin- 

 ished by rapacity of collectors. 



Of minor causes several are locally as potent as the main 

 causes in bringing about the disappearance of plants. We may 

 instance the following : — 



■ B^irning of fu7'ze and heather. — In Galway and in Donegal, 

 the burning and grubbing up of furze or heather is responsible 

 for some changes. 



Action of steam-rollers. — In Counties Dublin and Wicklow 

 mosses and hepatics have disappeared from this cause. 



Cutting out of bogs for peat. — In Ireland where peat is 

 formed on a large scale, and where coal is not extensively 

 found, peat has been dug for ages, or turf has formed a sub- 

 stitute for it amongst the poorer population. In Limerick 

 extensive areas up to high altitudes have been thus denuded 

 of peat, likewise areas in Monaghan, Fermanagh, Donegal 

 (where both peat and turves are used), Tyrone, Armagh, Co. 

 Down (causing disappearance of My Ha a7iomala), Antrim and 

 Derry. An interesting article on peat moss industries 

 appeared in A^ature, Sept. 19, 1907, pp. 528-530. 



Lowcrijig of level oj lakes. — The low-ering of the level of 

 LrOUgh Neagh is responsible for the disappearance of Osmunda 



