138 Proceediiir/s of the Royal Irish Academi/. 



THE METHODS OF SURVEY. 



The observations which are recorded in the present paper, and on 

 the accompanying map, represent the results of about one hundred 

 days' field-work, carried out at intervals, chiefly during the winter 

 halves of the last four years. This intermittent way of carrying on the 

 survey was unavoidable owing to our spare time being limited, and 

 has, we must confess, many drawbacks, progress being necessarily 

 slow. More especially during the time when the associations were 

 being, so to speak, borne in upon us, i.e. in the earlier part of the 

 work, it was somewhat difficult to bear the facies of a particular 

 association in mind in such detail, during a period of perhaps two or 

 three weeks, that we could decide in a moment, on meeting with a 

 somewhat similar association, whether the new association was 

 identical with the old one, or whether it would entail a modification 

 in mapping. As our experience grew, however, this difficulty became 

 less and less felt. On the other hand, this mai)ping at intervals has 

 its compensating advantages, not the least of which is that ground 

 ali'eady mapped has necessarily to be traversed many times, and in 

 different directions, so that it is easy to check previous mappings. 

 "We have taken many opportunities of doing this, and in tliis way 

 most of our area has been gone over several times. The modifications 

 in our previous mappings which we found it necessary to make on 

 going over the same ground again have been, however, extremely 

 small ; and although we do not presume to suppose that our survey is 

 a perfect one, and incapable of further improvement, we have no 

 hesitation in publishing the results of it without fui'ther delay, in the 

 hope that it maybe useful, in conjunction with similar surveys which 

 have been carried on in the neighbouring island, in adding something 

 to our knowledge of the vegetation of the Eritish Islands as a whole, 

 and also that it may serve to awaken interest in the subject, and be 

 the forerunner of more work of the kind in other districts of Ireland. 



Eirst, as to the determination of the associations. It is, perhaps, 

 scarcely necessary to say that we use the term "association " in rather 

 a loose sense. Those who are familiar with work of this kind will at 

 once recognise this, and will see that many of our so-called associa- 

 tions are really " groups of associations " ; but pending a more definite 

 system of nomenclature, we think the use of the word will be 

 sanctioned, and its meaning generally understood. 



AVe decided at the very beginning to avoid reading up the detailed 



