CO- OPERA TION. 177 



then so liable to be nipped by frost, nor even to be 

 eaten by birds. 



Co-operation, so far as it means differentiation 

 for purposes specially beneficial to the community, is 

 even further carried out among leaves than flowers. 

 We have seen that they are frequently modified, not 

 only into bracts, but into such other altruistic 

 states as thorns, tendrils, etc., all of which exist for 

 the wellbeing or defence, not of the individual, but 

 of the plant or community. 



The co-operation of the perfumes of small flowers, 

 the odour of each of which would be scarcely dis- 

 tinguished by itself, must be of great advantage to 

 them in attracting insects. It will be observed what 

 a large number of species of plants bearing very 

 small flowers have no other colour than white or 

 yellow. It is almost certain that few others are 

 visited by moths, for no other could be seen, and 

 the larger proportion of white flowers producing 

 sweet perfumes over those of any other colour, has 

 already been commented upon. 



The law of co-operation is often adopted by fruits. 

 What else can we denominate the clustering together 

 of the almost microscopical fruits of the Strawberry 

 upon their succulent receptacle — of the association 

 of such perfectly -developed " bird -fruits " as the 

 Dewberry, Blackberry, Raspberry, Cloudberry, and 

 others in a common cluster ? Small fruits have 

 assumed exactly the same associated and combined 



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