150 BOTANY. [chap. iv. 



modifications of inflorescence over previously existing 

 ones that favoured cross-fertilization, have predominated 

 in the struggle for existence, continually being carried 

 on amongst new structural departures from the older 

 forms. In the early types of flowers possessing colour, 

 the herald of all those various complications eventually 

 evolved for purpose of cross-fertilization, and which still 

 retain perfectly the power of self-fertilization, illustrated 

 by many of the lilies, geraniums, buttercups, roses, etc., 

 we find the flowers large and presenting a blaze of 

 colour, in fact division of labour and the formation of 

 communities for mutual good were ideas not evolved at 

 the early period of the cross-fertilization epoch, and why 

 the above-named plants along with numerous others 

 have never passed beyond this phase cannot at present 

 be explained; however, numerous other plants have 

 broken away from the old extravagant state of things 

 where each individual flower had to do everything for 

 itself, and consequently assumed large dimensions for 

 the purpose of making its presence known to insects. 

 The line of departure consisted in reducing the size of 

 the individual flower, and at the same time in concen- 

 trating numerous flowers into a cluster, the gain being 

 an enormous saving of material, without sacrificing the 

 primary object of colour and scent as advertisements to 

 insects, this principle being equally efi"ective in a large 

 quantity of small flowers massed together as in isolated 

 large flowers. A comparison of the dense mass of indi- 

 vidually small flowers forming the inflorescence of the 

 lilac {Syringa vulgaris) , with the large solitary flowers of 

 the red corn poppy {Papaver rhceas^, will illustrate the 

 above-stated view. 



