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BE^sa?^i2jai&»"^s 



PHYTOLOGY. 



BEYOLOGIGAL NOTES. 



Dr. Buchanan White has kindly sent me specimens of what he considers 

 to be his Hypnwn Braedalbamnsc, and, after careful examination, I cannot 

 help thinking that they are clearly referable to Hypnum subsulcatum, 

 Schpr. Synop. , which latter again cannot well be anything else than one of 

 the innumerable forms of Hypnum commutatum. Dr. White's specimens 

 show a very sportive nerve. Sometimes it is long; sometimes it is so short 

 as to be almost obsolete; sometimes it is narrow and rather prominent; 

 sometimes it is broad and fiat ; usually it is single ; but very frequently it 

 shows a very decided tendency to split up into two or three forks. This 

 form is plentiful near the summit of Ben Lawers, and occurs occasionally 

 on others of the Scottish mountains. 



Accompanying the specimens of Hypnum Braedalbanense was part of the 

 original specimens of Hypnum rupestre, B. W. , sent to Wilson and Schimper. 

 and declared by the former to be unknown to him, and by the latter to 

 belong to a new species. Were it not for the decisions of these great men 

 I should have had not a shadow of hesitation in declaring the plant to be 

 Hypnum callichroum, Bridel, for I am unable to defect a single point in 

 which the one differs from the other. * 



Much more perplexing are the original specimens on which Wilson founded 

 the species Grimmia sicbsquarrosa. Those which Dr. Buchanan White has 

 also sent me were first gathered by him on Moncreiffe Hill, near Perth, in 

 1864. At once they strike one as remarkably similar to Grimmia tricho- 

 phylla and G. Muhlenbeckii; and it is between these two that Gr. subsquat - 

 rosa must rank if a separate position is to be assigned to it. From both 

 of these it differs in the denser ramification, in the leaves being more or 

 less suddenly enlarged and crowded towards the apices of the branches, 

 more rigid, and when wet, subsquarrose. The last character does not seem 

 to be a very constant one. On closer examination under the microscope, 

 G. subsquarrosa differs from Muhlenbeckii (the margins of the leaves of 

 which, by the way, are rarely, if ever, quite plain, as described by Schim- 



* " H. rupestre now appears to me to be rather too closely related to H. calli- 

 chroum ; but as Dr. Schimper considers that it has claims to distinctness, I 

 think it as well to leave it as it is."— F. B. W. W. in Trans. Ed. Bot. Soc. 1867. 

 Wilson also changed his opinion, and referred the moss in question to H. 

 hamulosum. To a great extent I agree with Mr. Fergusson. — F. B. W. W. 



