BOTANICAL SUBJECTS. 65 



The reader might ask — how is it that, when two separate flowers 

 fuse, all their parts do not exactly double ? 

 There may be various reasons for this : but 

 (a) As a matter of fact we know that when two flowers fuse, 

 this muhiplication by tioo of all the parts of the com- 

 ponent flowers rarely happens. They do not always 

 double their parts all along the line. Sometimes they 

 do, but oftener there is some suppression of parts. 

 (6) The sepals and petals are comparatively of little importance 

 to the individual, and therefore, in the struggle for life, 

 many of these parts may disappear altogether, without 

 afPecting the fertilization and the maturation of the seed, 

 (c) Want of space and sustenance may be two great reasons 

 why, in fusing, certain parts are suppressed, and this 

 may not impossibly be one of the reasons why, in cross- 

 ing certain flowers, the seedlings produce occasional 

 double flowers. The doubling may be a reproduction of 

 the petals suppressed by the act of fusion in some ances- 

 tral form, and kept dormant by heredity until disturbed by 

 crossing and pushed forth again by luxuriant cultivation. 

 What determines the complete doubling of all parts, or the 

 doubling of some parts and not of others, or the amalgamation of 

 some parts of the one and the whole of the other, or the symmetry 

 of disposition of the various parts, is more than I can say. All 

 that can be said is that flowers do fuse, and that the resulting, 

 amalgamation may be the exact double or not ; and that such 

 fusions may have been important factors in the modification of 

 plants belonging to the same alliance. 



Look at Diplolcena Dampieri (Rutaceas). To my mind its 

 inflorescence gives distinct evidence that it originated in a fusion 

 of a number of single flowers ; or it may be that it was originally 

 a capitulum, and in other genera is split up into a raceme, and 

 Diplol^ena has remained as a relic. 



In Diplolcena a large number of bracts, forming an involucre,, 

 and representijig probably the fusion of the original cali/ces, 

 enclose a crowd of stamens. This is what Baillon says of it : — 

 " Its inflorescence recalls a veritable composite capitulum ; the 

 flowers have iit calyx, are sessile, and crowded together on a plane 

 surface, and enclosed in an invohicre formed of a large number of 

 imbricated bracts." 



A p.1742. E 



