THE STUDY OF THE EVOLUTION 



W 



267 



Vascular Structure. 



The sections examined were 



obtained from very yoang flowers. 



The following 



description relates to the series through the oldest flower obtained prior to the upgrowth 

 of the integument. 



The toral vascular cylinder separates to form an outer series of fourteen bundles, 



which extend upward in the 



y-wall toward 



petals and stamens (Text-fi 



E 



AG, st and j9^), and an inner series of fine strands (B-E, in ser). 



The bundles of the outer series branch before leaving the ovary to form scries 

 inwardly extending strands (G, ovy). The latter behave in an irregular manner, b 

 could not bo traced into the style, and clearly correspond to the middle ring of bundles 

 equivalent to dorsal and lateral carpcllary bundles — present in Davldla. 



I 



The bundles of the inner series are feebly differentiated, and extend as far as the 



insertion of the ovule (E, m ser) : some originate directly from the tornl 



point of insertion 



cylinder (B, in ser), passing internally as far as the axis of the fl 



and upward in the ovary 



level (C, D). 



the rest arise from the 



the 



ter bundles at 



outward 

 I higher 



Th 



} connection with the ovule could not be definitely settled. A small branch, o, 

 could be traced from ov 1 (E), so that it is possible that branches from ov 1 and ov 2 unite 

 to form the ovular bundle. Higher up in the series (F) the bundles ov 1 and ov 2 are 

 still evident and ov 1 is present in the style (H). The remaining bundles of this series 



g 



o 



CE) 



extend into the style (H). The bundles of the inner 



series are clearly 



ed with supply 



ith 



espond with the innermost or septal bundles of Davidi 



Clarke 



and appear to 

 * view of the 



bicarpellary condition of Mi 



partly depended upon tracing 



dorsal ribs of the 



rpels into the style, but it is now evident that the so-called dorsal ribs are merely 



Uections of small ovular strands. 



The axial extension of certain branches of the inner series at the base of the single 



loculus in M. platanifolia is curious, but M. hegonifolia 



often bilocular, and it is 



not 



probable that the branches which 



inf ralocular in M. platanifolia pursue 



iptal or axial course in bilocular forms of M. hegonifolia 



Nature and Origin of the Flower. 



The position of Alangium and Marlea 

 dilates between the Combretaceae and Coi 



the systems of differen 

 3R. De CandoUe t, who 



thorities, 

 followed 



byLindleyt, and for a time by Endlicher§, established these genera in a separate 

 family, the Alangiese, on the Combretacean s 



de 



an arrangement that, at the time 



seemed consistent with the occurrence of multiseriate 

 in both the Alangieae and Combretaceae. 



and 



unilocular ovary 



• B. Clarlve in Hook. Kew Journ. ii. (1 850) 129 

 t J. Liodley, Yeg. King. 2nd ed. 719 (1847;. 



t A. P. De Candolle, Prodr. iii. 203, 

 § S. Endlicher, Gen. PL 1184. 



