242 BOTANY OF THE LIVING PLANT 



comes first in the individual life, so as to supply the necessary materials for 

 propagation. Once these two pristine functions were allocated to distinct 

 regions of the plant, each was open to its own distinct specialisation. And so 

 it comes about that while in simple cases there may be some similarity 

 between the flower and the foHage shoot, the two may diverge widely in more 

 advanced types. But however greatly they may differ, the flower and the 

 foliage shoot are to be held as the results of segregation of parts of an 

 originally general-purposes shoot. This gives a natural meaning to those 

 structural resemblances, which are sometimes so striking, between the foliage 

 shoot and the flower which it ultimately bears. 



In such discussions as this the antithesis between the flower and the foliage 

 shoot is apt to be drawn more strongly than the facts warrant. The flower 

 is not always clearly defined from the vegetative region. Comparison of the 

 flowers of Cactaceae and Magnoliaceae, and of some Grasses such as 

 Streptochaete, show that bracts may merge gradually into floral organs. A 

 further comparison with Conifers, Cycads, and Club-Mosses will confirm the 

 view that the two regions have not always been as distinct as they now appear 

 to be in the Higher Flowering Plants. 



The more important lines have now been sketched along which 

 the analysis of floral construction may be undertaken. Such analysis 

 is a necessary basis for comparison, and ultimately for classification. 

 But it will not be pursued further at present. It is also necessary as 

 a step towards realising how the mechanism of the flower works. 

 An engineer cannot properly understand his engine till he has taken 

 it down. But the engine will not work till the parts are again assem- 

 bled. Similarly the student must not be content with the mere 

 analysis of the flower. After analysis he must assemble the mechanism 

 again, and study it as a whole. Each flower functionates as a whole, 

 just as much as any machine. Each part has its proper function 

 leading towards the common end. That end is the production of the 

 germ contained hi the seed. The transfer of the pollen is only one step 

 towards that end, and a comparatively early one. It is carried out in 

 relation to the showy parts unfolded at the time of blooming, and 

 thus gains an undue prominence. But the interest does not stop 

 when the flower fades. Fertilisation, which follows after blooming, 

 is actually the central feature, for it initiates the germ. It is a necessary 

 prelude to the nursing of the germ within the ovule. The protection 

 of the ovule meanwhile within the carpel, itself either free or sunk 

 into the tissue of the axis, is also important as contributing to the 

 final result. Not only then should the flower itself be studied as a 

 whole, but the propagative process also ; and PolHnation, with its 

 accessories of form, colour and scent, should be put into its proper 



