THE PRINCIPLE OF ADHESION. 83 



SO, however, in ArisfolocMa, acaording to Van Tiegtem, 

 tliouo-h often described as such* 



To summarize the above remarks, it seems clear that all 

 adhesions between the two whorls of the perianth, to be 

 found mostly in the CalyciflorcB, is an accidental occurrence 

 due to the hypertrophied condition of the axis in forming a 

 receptacular tube ; so that the term " perigynous " is more 

 strictly applicable than " episepalous." 



Adhesions between the filaments and corolla, or calyx if 

 the former be wanting as in Baplme, is an adaptation to insect 

 fertilisation ; whereby a more rigid position is acquired for 

 the stamens, coupled with a gain of leverage, etc. 



Lastly, adhesions between the stamens and pistil only 

 occur whei-e there is a receptacular tube, or "disk," as in 

 Nymphcea ; and the fusion of filaments with the style, or 

 between anthers and stigm^as, is brought about by the very 

 close proximity of the organs when in an early and undif- 

 ferentiated state. 



* Duchartre, Elem. de Bot., p. 648; Henfrey, I.e., p. 125 ; Bentli. and 

 Hooker, Gen. PL, vol. iii., pt. 1, p. 123; Van Tieghem, Traite de Bot., i., 

 p. 422. 



Van Tieghem's description and figure (Fig. 21) is as follows : — 

 " The styles and stigmas are abortive, and the six carpels ,,.^,,/,-s, ,-^ 

 are reduced to their ovaries. It is, then, the thickened "^ 

 connectives of the anthers, coherent laterally into a tube 

 and covered above with stigmatic papillae, which now play 

 the part of stigmas and of the style." 



To judge from Payer's figures (Organogenie, pi. 91 and 

 pi. 109), the stigmas appear to rise from the inner side of the 

 very short filaments, and might be interpreted as truly car- 

 pellary stigmas, but fused to the former. A further investi- 

 gation of the distribution of the fibro-vascular cords should Fig. 21.— Aris- 

 be made. Moreover, Asarian does not appear to have any- yau^^neghem)! 

 thing so abnormal. 



