DIALYSIS. 113 



and Nassauvieee belong. The abnormality in Anthemis 

 is of the nature of a reversion towards a condition in 

 which zygomorphism is not so pronounced as it is 

 ill that of the extreme ligulate type of ray-floret. 



The corona of Narcissus tends to become partially 

 or completely split up, especially in double flowers. 

 This subject will be more fully referred to on a 

 subsequent page. 



(3) Andeceoium. 



The possession of adelphous stamens, in which a 

 larger or smaller number are united for the whole or 

 a portion of the length of the filaments, is a charac- 

 teristic of certain orders. For example, the Malvacege, 

 Leguminosee, and Cucurbitaceee. This is also a more 

 lately acquired character. 



When the balance of the plant becomes upset from 

 whatever cause, inducing virescence and doubling, etc., 

 there is nearly always the tendency introduced to revert 

 in one or the other character to a simpler and more 

 primitive condition. Thus it was found in plants 

 6f Trifolium repens whose flowers were afflicted with 

 virescence in the pistil, that the column of nine stamens 

 had become broken up into its constituent parts, all the 

 stamens being separate and outspread. 



A similar dissociation of the stamens composing the 

 column of the Malvaceae is a concomitant of doubling 

 of the flower in many cases, as has been noticed in the 

 hollyhock {Althsea rosea). 



The stamens of the Fumariacese are for the most 

 part diadelphous. In the transverse plane are two 

 groups; each of these consists of a stamen of the 

 outer whorl united on either side of it with a mono- 

 thecal stamen from the inner whorl. Dissociation of 

 these stamens has sometimes been observed, as in the 

 interesting case mentioned by Wydlet in the bleeding- 

 heart {Dielytra spectabilis), in which all six stamens 

 (metamorphosed into small foliage-leaves) were per- 



VOL. II. 8 



