EVIDENCE FROM COLONIAL OR COMPOUND ANIMALS. 303 



the centauries (Fig. 202,0) are developing, into long petal-like organs 

 (Fig. 200, r\ Moreover, these outer florets are losing the repro- 

 ductive organs they still possess in the dandelion. The stamens 

 have disappeared in the outer white and yellow flowers of the daisy 

 and marigolds respectively, leaving the pistil alone represented (Fig. 

 200, r, sg); whilst the yellow central florets (d l d*} possess both 

 stamens and pistil, and are therefore the 

 true producers of seed. It is foreign to 

 our present inquiry to notice how this 

 arrangement of the flower parts, by placing 

 the brightly coloured parts on the outside, 

 imparts to these plants their conspicuous 

 nature, and thus, by attracting insects, 

 gives them a very marked advantage in 

 the struggle for existence, through securing 

 more frequent fertilisation. How or why 

 this greater attractiveness has been ac- 

 quired is immaterial. That which is all- 

 important for us to note is, that concur- 

 rently with a conspicuous dress, there is 

 being developed in such flowers as the 

 daisies and marigolds a return to that 

 singleness and individuality which was in 

 all probability once represented in their 

 race, before the work of aggregating once 

 separate flowers to form one flower-head 

 had begun. -The thistles remain types of 

 a true flower-colony. The dandelions and 

 centauries lead us from the thistles with 

 similar florets to an intermediate type, 

 wherein we see being developed those 

 features which, along with abortion of 

 part of the outer florets, are causing the 

 compound flower to assume the dress of 



its simple neighbour ; whilst in the daisies specialisation has advanced 

 a step further, and has developed a very marked likeness to the simple 

 flowers around. If these modifications progress in the future as in 

 the past, we may naturally expect that the " floures white and rede " 

 of Chaucer, and their allies, will develop a still more marked indi- 

 viduality, and will leave the lower compound nature of their race 

 further and further behind. 



It may be, lastly, Interesting to note that the crowding together 

 of flowers on a "flower-head," seen in the daisies and their 

 neighbours, is susceptible of explanation through a study of the 

 modifications and gradations witnessed in the arrangement of flowers 



FIG. 202. Centaurea cyanus, or 

 CORN BLUEBOTTLE. 



