124 The Scottish Naturalist. 



Dr. Braithwaite, in the Journal of Botany, following out Mitten's 

 principles to their natural limits, unites Gymnostomum and 



Weissia and retains the latter name for the genus so enlarged. 

 Thus Gymnostomum calcareum and G. commutatum become 

 with him who abolishes the genus Gymnostomum, Weissia cal- 

 carea and IV. commutata respectively. Mr. Hobkirk, whilst 

 retaining the genus Gymnostomum after Wilson, adopts the 

 generic names of these recent aditions to our Moss-Flora, as 

 given by Dr. Braithwaite and includes them in his own and 

 Wilson's genus Weissia^ forgetting evidently one of two very 

 important things ; either that he had in his Synopsis a genus 

 Gymnostomum for the express purpose of embracing what some 

 would call non-peristomical Weissice ; or that the two mosses 

 above-mentioned have no peristome ! 



A good deal may be said with regard to nomenclature, and 

 two or three passages in the work before us give us an oppor- 

 tunity of touching on a point connected therewith. It is 

 allowed on all hands that the name first given to a species 

 should adhere to it ever aftei wards, if possible, and that the 

 name also of the nominator should be added thereto. Some- 

 times it is not possible to retain the generic name of a plant 

 owing to the many changes which take place in men's ideas 

 regarding genera, but in nineteen cases out of twenty it is 

 possible to retain the specific name. Now we hold that the 

 names of the original nominators of plants — the names of those 

 who first distinguished them as species — should alone be 

 attached to them as the names of their nominator. This is 

 too frequently disregarded at the present time. In his Synop- 

 sis Mr. Hobkirk, for example, associates the name of Mr. 

 Carruthers with Seligeria paucifotia as its nominator. Why 

 should this be so when the plant was well known to, and named 

 by, Dickson seventy years ago ? And yet Dickson's name is 

 never mentioned in connection with it ! It is true he called it 

 Bryum paucifolium, but everything almost was a Bryum or a 

 Hypnum in his day, and genera had then much wider limits 

 than now, though their limits have been once more expanding 

 of late. Again, the name of Dr. Braithwaite is associated with 

 Tortula rufa, which species all allow to have been first dis- 

 tinguished and named by Lorentz, who called it Didymodon 

 ntfus. But Mitten believes that Didymodon^ Trichostomum, 



