No. 494] 



PAh'Asrnc ri.Ax / > 



105 



branches, leaves, flowers and fruit. These plants have 

 discarded most of those essential parts, none of them 

 having more than a short stem besides the fertile flower ; 

 and the sessile species, which are numerous, retain only 

 the flower. Such a conception would therefore carry with 

 it the idea that those eliminations were consecutively 

 effected until the lowest structural limit was reached ; but 

 neither their own structure nor that of any other known 

 plants affords the least indication that any of these para- 

 sites reached their present condition by either selective 

 gradation of successive steps. The Rafflesias, like the 

 mistletoes, are parasitic upon trees, and the seeds of both 

 will not germinate successfully upon the ground. One 

 may well believe that when the mistletoes abandoned the 

 soil and inflicted themselves upon trees they took with 

 them, and retained, all that they then needed for their 

 support. But when the Rafflesias made their similar 

 change, as they are assumed to have done, they required 

 from their hosts the fullest possible tribute. Apparently 

 sure of receiving it, they discarded as no longer necessary 

 the principal part of their own somatic and blastema! 

 structures, the sessile species retaining only those parts 

 which are concerned in parturital reproduction, namely, 

 only the flower. Their success has been complete, for 

 although they are rootless, stemless, branchless and leaf- 

 less plants, and originate from a structureless embryo, 

 they are among the most vigorous of vegetable forms, 

 the flower of the largest species sometimes reaching a 

 diameter of more than three feet. One cannot conceive 

 of a wider departure from normal conditions than is pre- 

 sented by group VI, or of a more complete isolation of 

 structure and habit from all other plants. 



Group VII, which is represented by the Balanophoreae, 

 is remarkable for the comparatively large number of sys- 

 tematic genera which it embraces, some of which are so 

 greatly differentiated from others as to deserve recog- 

 nition as sub-families. Some are comparatively incon- 

 spicuous; some produce large, showy flowers, and some 



