COMPOSITE. 119 



consist in the different length of the florets, rendering 

 the honey more or less accessible to insects ; in the 

 arrangement of the stamens and pistil ; and in the 

 character of the outer, or " ray " florets. 



In some of the Compositae the florets all contain 

 both anthers and stigma. Generally, however, the ray 

 florets develope no anthers, but a pistil only ; while in 

 some species of Centatirea they are barren, and merely 

 serve as flags. It is remarkable that in C. nigra, 

 while the outer row of florets generally resemble the 

 rest, they are sometimes enlarged and neuter, as in C. 

 cyanus, &c. As regards the relation to insects, we 

 find every gradation, between Taraxacum, Cirsium 

 arvense, and Achillea, on the one hand which are 

 conspicuous, rich in honey and much visited by 

 insects ; and on the other, Senecio vulgaris, which is 

 rarely visited by insects, and the species of Artemisia, 

 which are said to be wind fertilised. 



In Tussilago farfara the disk florets give honey 

 and pollen ; the ray florets contain neither, but render 

 the flower-head conspicuous, and produce seed. 



In the common Feverfew, or large white Daisy 

 (Fig. 86), (Chrysanthemum parthenium), which has 

 been well described by Dr. Ogle, " Popular Science 

 Review," April 1870, the flower-heads consist of 

 an outer row of female florets, in which the tubular 

 corolla terminates on the outer side in a white leaf or 

 ray, which doubtless is useful in making the flower 

 conspicuous. The inner florets are also tubular, 

 but are small, yellow, ^.nd without a ray. Each of 

 these florets is furnished with stamens as well as a 

 pistil. The anthers are united at their sides so 



