392 Floristik, Geographie, Systematik etc. 



of 68 monographs now in course of preparation. Cläre Island 

 lies 3 miles from the west coast of Ireland amongst other islands; 

 in size it is the largest (6 sq. miles), and it is the highest (500 

 metres). The western side is cliff-bound and very exposed to the 

 Atlantic storms, and although man has influenced the Vegetation in 

 some degree, yet the rugged topography has limited population and 

 cultivation to sheltered parts, mainly towards the eastern side. The 

 extend and character of the flora (p. 2 — 14) is examined by com- 

 parison with that of neighbouring islands and the Mulle t, the 

 nearest part of the mainland, all of which have been described in 

 earlier publications by Praeger. The flora is relatively large (393 

 species) as a result of Variation in habitat, and it is almost entirely 

 made up of calcifuge plants. The Vegetation of the island is illustrated 

 on a map. Maritime formations are poorly represented, but Plantaga 

 maritima sward occurs extensively on the cliff-tops. Natura] grass- 

 land is restricted to sheltered parts near the area of cultivation. 

 Woodland is extremely limited but in former times was more 

 extensive; there is still one area of dense scrub (l — 2 metres high) 

 of Corylus Avellana, Betula, Hex, Pyrus Aucuparia, Quercus sessili- 

 ßora, Salix, etc. with a varied shade-flora. Moorland is extensive 

 and is represented on the map by three formations: Calluna- Erica, 

 Calluna-Eriophorum, and Calluna-Eriophorum-Juncus squarrosus. 

 Alpine Vegetation occurs on a rugged crag (460 m.) where 10 

 "highland" species and many other species find shelter in fissures 

 and on shelves. An annotated list completes the descriptive part. 



The influence of man upon the flora (p. 31 — 54; is a useful 

 summary of the many ways in which man leaves his mark on 

 Vegetation. The sources of introduction to Cläre Island are dealt 

 with in considerable detail and a nomenclature is suggested to 

 express whether source, dispersal, and habitat are natural or artifi- 

 cial; the analysis leads to the conclusion that out of 393 recorded 

 species, about 338 are true natives; for details the original must be 

 consulted. The origin of the flora (p. 54 — 96) is fully discussed. In 

 the case of Cläre Island, transport is resolved into three modes: 

 water, flying creatures, and wind. Transport by water is not regar- 

 ded as of great moment as a means of colonisation. Wind-transport 

 is considered at length, and the author gives in detail the results 

 of a number of experiments made by him on the time taken by 

 seeds allowed to fall a measured depth; the application of such expe- 

 riments to wind-transport is thus illustrated: "A seed with a high 

 index of efficiency (e. g. Epilobium montanum which takes 20 seconds 

 to fall 12 feet) is liberated 5 miles from an island with a favourable 

 gale blowing at 50 miles per hour; the seed would take only 6 

 minutes to traverse the horizontal distance, but during that time 

 its fall would amount to 216 feet." As a general conclusion on 

 transport the author considers that out of 393 species, 15 may 

 have been introduced by water, 50 by wind, 55 by man, leaving 

 270 species to be carried by birds or in some other way. The pro- 

 bability of a land-bridge as a means of o Verlan d migration is favou- 

 red by the author. The plates illustrate types of vegetation-cliff , 

 Plantago sward , Osmunda regalis, Silene acaulis, Saxifraga decipiens, 

 etc. There is an extensive bibliographj^, mainly relating to plant 

 distribution. W. G. Smith. 



Priestly, J. H., The Pelophilous Formation of the left 



