BOTANICAL NOTES. 205 



existence can be traced to the absence, or extreme dilution of the only 

 two colouring agents hitherto discovered in plants, clorophyl and chromule; 

 and consequently they may be expected to occur, under certain conditions, 

 in flowers of all colours, from the deep blue tints of the Cyanio series, as 

 seen in many hyacinths, to those of the xanthic, or yellow series, so pre- 

 valent in the Ranunculacece. 



As instances of this transmutation of colour, we would specify the fol- 

 lowing as among the more important that have come under our ob- 

 servation : — 



SympJiytum officinale, (Common Comfrey,) with flowers of a dirty white 

 colour, and in this respect almost identical with S. tuberosum. This variety 

 we have seen only by the side of an old wall at Rubislaw, about a mile 

 distant from Aberdeen. This station is also well worth a visit, from the 

 fact of its producing Tcucrium chamoedrys, (Wall Germander,) a pretty 

 little plant, which beginning to flower about the end of July, bedecks part 

 of the wall with its spikes of small pink flowers, well relieved against its 

 dark evergreen leaves, all over the autumn months; and, indeed, on visiting 

 the spot in Kovember last, we saw many specimens still in flower. 



FoJemonium cceruleum, (Jacob's Ladder,) we have gathered by the banks 

 of a stream in the same neighbourhood, in one season of the purest white, 

 while in another we found onlj specimens of the common blue colour. 



Vicia sepium, (Hedge Vetch.) — We have seen specimens of this plant 

 with white flowers, only in the parish of Auchindoir, in this county. 



Cnicus palustrisj (Marsh Thistle,) is by no means unfrequent in this 

 quarter with white flowers. 



Campanula rotundifolia, (Bell Flower,) is also of not unusual occurrence 

 with this peculiarity. We have likewise observed in some plants a decided 

 tendency to produce double flowers. 



C. latifolia, on the banks of the Don, above Breda, in Alford, (white.) 



Pedicularis palustris, (Marsh Lousewort,) producing white flowers, we 

 have seen only near the upper course of the River Dee, as at the well- 

 known Linn, and all along Glen Dee, to the foot of Ben Macdhui. 



The three British species of Heaths, which occur in this district, are 

 all occasionally to be met with of a white colour, and then present a very 

 pretty appearance. We refer to Erica tetralixy E. cinerea, and Galluna 

 vulgaris. The former, however, surpasses the other two in variety of 

 colouring; in some young patches of this species we have observed four or 

 five difierent varieties, ranging from the white or pale rose-colour to the 

 deeper shades of purple. 



Galeopsis Tetrahit. — With us appears in tints equally diverse with those 

 assumed by the plant of which we have just spoken, and certainly presents 

 a better claim to the specific versicolor than the species which now bears 



