46 TRANSITIONS OF LEAVES [CH. 



system ; and, indeed, there are shoots which consist only 

 of a flower or a cluster of flowers. 



In pursuance of this idea of the shoot-nature of the 

 flower, we may consider for a moment some notions, the 

 rudiments of which have been entertained in years gone 

 by, by observers and thinkers who were struck with the 

 above suggestive resemblances of the parts of the flower 

 to leaves, but who had to struggle with their concepts 

 insufficiently provided with a knowledge of development 

 and with what goes on in lower plants. 



It may be suggested that an ideal plant would show, 

 proceeding from the base of the shoot upwards, some such 

 changes as the following, occurring on the axis. 



First we have the Cotyledons, then the Scale-leaves 

 and Foliage-leaves which even on an ordinary plant 

 exhibit many individual differences of form, size, &c., in 

 the lower, middle and upper parts of the shoot ; then 

 come the Bracts and Floral leaves, and stress may be laid 

 on the evident tendency of the bracts to depart more and 

 more from the type of the foliage-leaves, and often to 

 approach the parts of the flower in character, and of the 

 latter to diverge still more from the leaf type as we pass 

 from calyx to stamens. 



In spite of many mistakes, and not a few absurdities, 

 perpetrated in this connection, the notion of an ideal 

 shoot is a useful one, and the facts referred to may be 

 compared with what is shown in Fig. 14; and if we 

 suppose the internodes between the different series of 

 floral leaves to be shortened, and these leaves themselves 

 to be definitely grouped into whorls or close spirals, w^e 

 obtain a fair idea of the flower as presented by the vast 

 majority of the higher plants. 



The principal reason for the popular impression that 

 the flower is something quite different from other parts of 



