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and Continental — of Salix fragilis and 8. viridis require careful 

 revision, since many of the existing citations have not been, it 

 would seem, verified by personal examination of the works cited. 



Both Wimmer and Andersson appear to be of opinion that 

 viridis rarely, if ever, occurs otherwise than as an introduced 

 plant, "Whether this be the case in Britain, further investigations 

 are required to show, but it is probable that it occurs sponta- 

 neously (i. e. self-sown) and as wild, but not more so, as either of 

 its parents. From the nature of some of the forms it is likely 

 that they have arisen from variations in the mode of cross-fertili- 

 zation, some having sprung from fragilis $ X alba $ or vice versa, 

 and others from the crossing of viridis with one of its parents. 

 Differences, too, have probably originated through one or other 

 ot the two varieties of fragilis being concerned in the parentage. 

 Experiments like those conducted by Wichura are necessary to 

 decide these questions. 



S. viridis has been found in the following counties :— 2, E. 

 Cornwall (^cAer5r% 5 ); 3,8. Devon (Archer Briggs); 13, Surrey 

 {Winch, A. Bennett) ; 19, K Essex (Leefe) ; 23, Oxford (G. O. 

 Bruce) ; 29, Cambridge (J. Holme) ; 30, Bedford (C. Abbot) ; 37, 

 Worcester (B. F. Towndrow) ; 38, Warwick (T. Kirk) ; 80,Rox- 

 burgh (A. Brotherston) ; 83, Edinburgh (Boswell Sgme); 88, Mid 

 Perth ! Possibly also in Stafford and Derby. 



B. DIANDE^E. 



Group 4. Capeej. 



This group consists of a number of very closely allied species, 

 three of which have been found in Britain. These three— 8. 

 nnerea, L., & aurita, L., and S. Caprea, L — are the most widely 

 distributed members of the group, occurring throughout Europe 

 at . lea8t - Whether they are really distinct species is a disputed 

 poiut, but salicologists on the whole are tolerably unanimous in 

 ^taming them as such, although it is not to be denied that, either 



y ^termediate or hybrid forms, they are so closely connected 

 , at it is difficult to point out distinctions which will hold good 

 ! n ever y ca se. Wimmer, however, is of opinion that when studied 



u 7 m S st ate they may be separated without much trouble 

 * n opinion for which there seems to be justification, but which 



068 not a Pply to the determination of dried, and consequently 



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