184 THE SCOTTISH BOTANICAL REVIEW 



Some of these plants are normally creeping and prostrate, and 

 form adventitious roots, e.g. Lycopodinni alpi?ium and Carex 7-igida. 

 But it is found that a similar habit is also common to CaUiina vulgaris. 

 Erica cinerea, and Airaflexuosa, as well as the species of Vaccifiiuni 

 and Arctostaphylos. The plants all grow prostrate in the direction 

 of the prevailing winds, and are subjected to conditions comparable 

 to the layering used by gardeners for the propagation of many 

 garden plants. The wind continually erodes the surface where the 

 plants are old and woody, thus destroying them, but the younger and 

 more branched parts of the plants are buried in drifted material, 

 thus inducing the formation of adventitious roots. This process 

 results in a constant migration of the plants in a definite direction 

 before the wind, and also leads to the peculiar wave-like troughs and 

 ridges already described in the "Vegetation of Caithness. " The type 

 of Calluna is probably the form Erikae of P. Graebner, since it 

 shows the geotropic curved extremities of the smaller branches. 



C. B. Crampton and M. Macgregor, 



Dear Mr. Editor, — It seems impossible to arrive at a full know- 

 ledge of the British Rubi by mere collection and comparison of 

 specimens. Might not something more be done by studying the 

 effect on a few definite species of artificial change of environment, 

 and of the results of crossing? If two small groups were studied in 

 this way — say Mr. Roger's suberedi and their hybrids with rhamni- 

 folius, Selmeri, macrophyllus, and corylifolius — might it not throw 

 much light upon the whole genus, and beyond that ? Short of that, 

 might not much be done by studying the position in which definite 

 species are growing with regard to "intermediates"? Is R. Rogersii 

 = R. plicahis X carpinifoUus ? Does R. suherectus x corylifolius simu- 

 late R. fissus ? Edw. G. Gilbert. 



Note on some vice-county records of Cornus suecica, Linn., etc. — 

 To the list of Scottish vice-counties from which Cornus suecica has 

 been recorded, given in Mr. G. G. Blackwood's interesting note in 

 the April number of the "Review" (p. 117), must be added 87 

 (So. Perth) and 1 1 1 (Orkney;. In the former it has long been 

 known to grow sparingly on Ben Ledi, where it was gathered by 

 Professor J. H. Balfour and party on 21st July i860, and in subse- 

 quent years, as recorded in his " Botanical Excursions," pp. 309, etc. 

 I have before me a specimen collected there so recently as July 1907. 

 The Orkney record — from the island of Hoy — is given by Mr. Arthur 

 Bennett in "Ann. Scot. Nat. Hist.," 1908, p. 251. To the English 

 vice-counties should be added 59 So. Lancashire {id., ibid., 191 1, 

 p. 190). William Evans. 



