'Z^O 



MORPHOLOGY OF MEMBERS. 



prolongation of the other. The growth of the mass of tissue lying between g and u further 

 continues in the same direction, and the whole lateral shoot assumes the form repre- 

 sented in H (Fig. I) ; the still further change of position of the parts which takes place 

 in consequence is explained by Fig. //, where ^n represents the bud u in ///, bl the 

 still more elongated sheath of the leaf bl in ///; the channel / is the cavity inclosed by 

 the leaf /^/increased in breadth, and which, were there no displacement, would be entirely 

 filled up by the bud u (or kn) ^. 



In order to make the following displacement, which occurs very commonly, more 

 intelligible, reference should be first made to Fig. ii8, p. 154. This shows how the 

 tissue beneath the apex expands laterally by early growth, so that the surface of the 

 growing point, which would otherwise be elevated in a cone, becomes almost level ; and 

 the apical point thus comes to lie in the middle of a plane instead of at the point of 

 a cone. In the Sunflower this state of things remains nearly unchanged as the capitulum 



Fig. 159.— Development of the fig of Fi'cus carica (after 

 Payer : Organogenie de la fleur). 



Fig. 160,— Development of the flower oi Rosa alpina (after Tayer 

 Organogenie de la fleur) . 



developes; but the abnormal growth increases in many cases to such an extent that 

 the apical point eventually lies at the base of a deep hollow, the walls of which result 

 from older masses of tissue, which properly lie beneath the apex, growing upwards and 

 overarching the apex itself. This occurs, for instance, in the development of the fig, 

 which, as shown in Fig. 159, is a metamorphosed branch, the apex of which is at /» still 

 nearly level, at // has already been outstripped by a circular leaf-bearing cushion, and 

 at IIP' is depressed in the form of an urn. The apical point of this shoot lies in this 

 case in the deepest part of the hollow, the inner side of which is properly only the 



^ [See also J. H. Fabre, De la germination des Ophrydees et de la nature de leurs tubercules, 

 Ann. des sc. nat. 1856, vol. V.] 



