CHAPTER III 



THE COLOURS AND PIGMENTS OF PLANTS 



Pigments and Colours of Bacteria and Fungi — Chlorophyll 

 and the Associated Pigments — Colour and Pigments of 

 Algse — Pigments of Flowering Plants — Autumnal Colora- 

 tion — Colours of Flowers and Fruits — Meaning of Plant 

 Pigments and Summary. 



In considering the colours and pigments of plants 

 we may conveniently begin with the colours of 

 Bacteria and of Fungi, and then pass to the con- 

 sideration of the colouring of chlorophyll-containing 

 plants. 



The colours of Bacteria are often surprisingly 

 brilliant. The red spots which Micrococcus prodigiosus 

 forms on moist bread, the violet colour which 

 sometimes appears on decaying meat, are familiar 

 cases in point, but less familiar forms are often 

 equally bright. There are some facts of interest 

 in regard to the position in which the pigments 

 occur, and the conditions necessary for their formation. 



As to the first point, the pigment may occur 

 within the cells of the colony. In 1873 Professor 

 E. Ray Lankester described an interesting peach- 



