190S. HoRWOOD. — Extinction of Cryptogams in Ireland, 153 



12. Browsing of sheep in confined sheep-pens. . 



13. Whaling industr}', pollution of stations with offal and 



refuse from whales. 



14. Use of sea-weeds (when not drifted) as manure. 



15. Dr3'ing beaches, clearing of vegetation for drying of 



fish. 



16. Marine denudation and erosion. 



17. Collection of mosses, &c., for table decoration, &c. 



Since this investigation has to do with abnormal external 

 conditions, and their efi'ect and extent, it is not concerned 

 with the question of the natural distribution of the plants 

 themselves so much as with the recent changes in the nature 

 ot their environment, due to abnormal climatic conditions or 

 causes observed as following in the wake of human industry. 



Effects. — Of the above causes (main or minor) only those 

 marked with an asterisk (*) have been reported so far as at 

 work in Ireland. 



Since the same causes that aff'ect Cryptogams likev.ise in- 

 fluence Phanerogams, information as to the latter is here 

 taken into account where it throws light on their extinction. 

 In estimating the effects it is to be noted that in some areas 

 no change has occurred, whilst in others external conditions 

 are even more favourable. The following is a summary of 

 the changes so far noted : — 



A. Climate — The climate of Ireland, except where locally 

 forests have been felled, as in Limerick, parts of Clare, 

 Dublin, Wicklow, Down, remains more or less unchanged. 

 Owing to the prevalent S.W^ winds, the smoke evil, such as it 

 is, and confined mainly to the east counties, is considerably 

 diminished. Desiccation i.s noticed on the east coast, from 

 Co. Down to Wexford, in abnormall}' hot summers. 



B. Spread of Civilization^ <2^v. 



Draijiaoe. — This is responsible for the disappearance of 

 some mosses and hepatics in Dublin, Wicklow, Down, 

 Antrim, and must be operative elsewhere, especially where 

 bogs have been drained. 



Cultivatio7i. — In Co. Cork, Co. Clare and Co. Galway, the 

 ploughing, tilling, and artificial manuring of lands has tended 

 to extinguish some species, 



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