CO-OPERATION. 173 



as in the CompositcB. Among some of the few 

 members of this community, however, we find the 

 same tendency as in the Umbelliferce above men- 

 tioned. In the Scabious, and more especially in the 

 Knautia {Scabiosa succisa and Knaiitia arvensis), the 

 flower-heads are merely collections of individual 

 flowers. In the Knautia it will be observed how 

 the outer members are larger and more conspicuous ; 

 and their lower parts are expanded so that insects 

 may alight upon them with the greater ease. The com- 

 munity, however, is advantaged by its outer members 

 being more highly endowed and specialised. Nobody 

 with common sense doubts this also is the case in 

 human societies ! 



Notice has already been taken (page 82) of the 

 reasons for the two different colours in members of 

 the Boraginacece — the old and the new being re- 

 latively blue and pink. There we have an illustration 

 of how the old flowers continue to help the juveniles 

 even when their own purpose has been effected. 

 Perhaps it may be hereafter found that the two 

 methods of inflorescence known as " regular " and 

 *' irregular " sometimes assist in the same patriotic 

 work. Nobody can doubt it is so in a cluster of 

 Apple -blossom, for instance. The central flower 

 opens first, and all round it is a ring of brilliantly 

 coloured, unopened flower-buds. Observe how all the 

 colour of the Apple -blossom is distributed over the 

 wider surface of the petal, whereas the nppej' surface 



