1897] NOTES AND COMMENTS 13 



its brilliant golden hue to a pigment called carotin (from its presence 

 in the carrot root), " which is amassed in discoidal bodies that nearly 

 rill up the cells of the epidermis, especially towards the base 

 of the petal ; in other parts, especially when the flower is fully 

 expanded, it seems diffused in oily droplets or amorphous granules." 

 In either case the starch grains in the subjacent tissue act as a 

 reflector, and contribute greatly to enhance the effect. The flower- 

 heads contain a considerable amount of sugar, starch, calcium oxalate, 

 and soluble phosphates, in these respects approaching more to the 

 character of leaves than is usual. The stem and root of this butter- 

 cup (Ranunculus bulbosus) are remarkable for the presence of an 

 acrid camphoraceous body easily decomposed into a volatile bitter 

 principle (anemonin) and an acid, even during the drying of the 

 plant, so that its original poisonous character disappears. 



Bird'S|foot trefoil (Lotus comiculatus), with the brilliant orange 

 and crimson tints of its little papilionaceous flowers, is known to 

 everyone. To produce this vividness and lustre the epidermal cells 

 are swollen into papillae, and contain no less than three distinct pig- 

 ments. There are the solid carotin corpuscles, and also two colour- 

 ing-matters in solution in the cell-sap. One is a clear, yellow juice, 

 the other is identical with the anthocyan of the rose. Where the 

 latter predominates we get the deep red colour. 



The tiny flowers of the cheerful little yellow bedstraw (Galium 

 verum) contain carotin, much yellow resinous matter, and " a curious 

 purplish substance (possibly purpurin) insoluble in cold alcohol or 

 benzene after purification." The flowers also contain a species of 

 ferment which, like rennet, has the power of coagulating boiling 

 milk. A substance known as rubichloric acid is present, not only in 

 the flowers but in the stem and root. It forms a colourless solution 

 in water, but when boiled with a few drops of hydrochloric acid, 

 suddenly produces a deep blue, then a green colour, and deposits a 

 dense, dark green precipitate soluble in ammonia. The disc florets 

 of the daisy are tinged with carotin granules ; the crimson of the 

 ray florets is due to a soluble pigment described as a tannin anhy- 

 dride. The blue of the harebell and chicory is again a tannin 

 derivative. 



Two colouring matters are engaged in the decoration of the 

 primrose. At the base of the petal-limbs, where the tint is more 

 deeply orange, carotin granules are present ; the rest of the corolla 

 contains a pale yellow, soluble pigment. Although the tints are 

 comparatively feeble, chemical analysis shows that the plant is 

 capable of " an infinitely richer wealth of coloration " than it shows 

 in our climate, since " it seems almost impossible to exhaust the 

 flower heads of substances which yield vivid and powerful orange 

 and yellow dyes." 



