144 THE NATURALIST. 



face. M. Boreau unites systyla and fastigiata together. R. leucochroa and 

 stylosa have white flowers, and leaves more like those of hihracteata and 

 arvensis than ccaiina. Whether these are inhabitants of Britain still re- 

 mains to be shown. 



To conclude with a general summary of what has been advanced with re- 

 gard to the affinities of the British species, we can perhaps best express their 

 mutual relationship by a diagram, in which canina is placed in the centre 

 of a circle, and the species which differ from it most at the circumference. 

 The result will then be something like the following : — 



As nearly as I can estimate, if we were to adopt with regard to the Bri- 

 tish Eoses, a similar rendering of what constitutes a species to that em- 

 ployed by M. Deseglise, in his " Monograph" for France, the following 

 would be the result : — 



Spinosissimse 8 



Villoste 6 



Bubiginosse 8 



Canin[e 28 



Systylse ^ 



Total 47 



