126 
The Irish Naturalist 
May, 
PLANT FORMATIONS OF THE DUBLIN MOUNTAINS. 
The Vegetation of the District lying South of Dublin. By 
G. H. Pethybridge, Ph.D., B.Sc, and R. I^loyd Praeger, B.B., 
M.R.I.A. Proceedings of the Royal Irish Academy, xxv., B. Dec, 1905. 
Pp. 57. Coloured Map. Five plates. Price, is. 
The publication of this paper marks the opening of a new era in the 
investigation of the plants of Ireland. The collector and enumerator 
of species has placed on record what plants are to be found, and during 
the last decade one of the authors of this paper has perfected the frag- 
mentary county lists until they are now a representative census. The 
Watsonian side of distribution has also received attention, and the great 
botanical divisions of the Irish flora are known, as well as something of 
their origin. Here and there a County Flora deals specially with the 
plants of a district and their distribution. Thus, from the oft depre- 
cated collecting of plants and making of lists, there has arisen a record 
of the plants of Ireland which has claims to be considered at least 
fairly complete. The progress, like that in most countries, has been 
mainly along floristic lines. Meanwhile, another branch of the out-door 
study of plants has been opening from a prolonged bud-stage, and the 
authors of this paper decided to test the merits of this recent growth, 
the study of plant associations. It is unnecessary to define or to 
describe this study, because in the introduction to the paper under 
review there is an excellent summary of the objects and the develop- 
ment of the subject. This introduction^ although it forms the first part 
of the paper, was probably the last part written, because the authors 
state (p. 138): "We decided ... to avoid reading up the detailed 
work done in Scotland and England^ and thus to start devoid of pre- 
conceived notions as to what the associations (if any) might, could, 
would, or should be, and to let them force themselves upon us as they 
actually existed in this area." This was the best test to make, and the 
result was : — ''We were not long in recognizing that associations did 
exist, and in deciding that they could be mapped, but onl}' on a map of 
a fairly large scale." The writer of this review was in some measure 
the means of suggesting the study of Irish vegetation on these lines, for 
one of the authors was present at the Glasgow meeting of the British 
Association (1901), when an attempt was made to explain the work of 
Robert Smith (died 1899), and to encourage its development in Britain. 
The criticism of one who had already done so much topographical work as 
Mr. R. Lloyd Praeger was awaited with somewhat mixed feelings, and 
it was a relief when, in course of time, one learned that the method 
was approved, because from his many-sided investigations on the Irish 
flora, Mr Praeger was better prepared than most men to judge of its 
value. Hence, though at first sight " The Vegetation of the District South 
of Dublin " may appear to be merely of local interest, it has a much 
wider value as a study in plant geography, and is in reality an important 
contribution. 
