THE STUDY 



rLOWEE. 2^3 



stylar canal is cross-shaped (in bilocular forms), and upon tracing it downwards the 

 longer arm passes into communication with the loculi and the shorter arm is distinctly 

 suturah The canal is sometimes three-lohed in unilocular ovaries. 



4 



The terminal ovules in bilocular ovaries are axially suspended, one in each loculus; 

 but traces of parietal placentae, absent in Cornus, exist immediately above the point of 

 insertion of the ovules (Text-fig. 10, G, pi). The ovules are radially orientated, as in 

 Sehcingia. The orientation is not disturbed in relation to the absence of the septum. 



Vascular Structure 



■ 



1 ' 



1 



Several hand-cut series and one by the microtome were prepared through unilocular 



t 



ovaries, whilst two series by hand and one by the microtome were taken through 

 bilocular ovaries. The last-mentioned microtomed series will now be described. Six 

 peripheral bundles {out ser) and one centrally-situated or axial bundle were present 

 below the loculus (Text-fig. 10, A). The peripheral bundles, branching and anastomosing, 

 increase upward to form an outer series of twelve bundles which are the traces of six 

 petals and six stamens, and some small inner branches (B-E). The majority of the 

 inner branches arise from the bundles near the septum on either side (D). They extend 

 into the septum, and strands from opposite sides {ov 1, ov 1', and ov 2, ov 2') augmented by 

 the axial bundle {ax) unite to form the ovular trace. Two bundles extend upward from 

 this level, but soon die out (E). In another flower four bundles were present at a 

 corresponding level, one in each placenta (G, ov). Two of the above-mentioned inneit. 

 branches (E, d) extend upward and occupy a dorsal position in the style (E). 



In unilocular ovaries, the . " axial " bundle is situated near the side of the loculus 

 (H, I), It extends upwards and is joined by inner branches corresponding to those 

 marked ov in D, so that an irregular arc or collar of vascular tissue is formed (J, K) 

 from which the ovular trace arises. 



The change to the unilocular condition is accompanied by the displacement of the 

 axial bundle, and by the diversion of the vascular tissue pertaining to the absent ovule 

 to the present ovule. 



Comparison with Cornus. 



CoroJcia was described by A. Cunningham * in 1839. Endlicher f at first placed it near 

 the Khamnacea^, but later % transferred it to the Cornacese, and it remains in this family 

 in the systems of Bentham and Hooker, Baillon, Harms, and "Wangerin. Corokia, 

 however, differs from Cornus in the followinsj details : — (1) the presence of parietal 



placentae immediately above the situation of the ovule; (2) the existence of an axial 

 bundle ; (3) the method of vascular supply to the ovule, and (4) orientation of the 

 ovule. Hence the structural agreement is not quite so close as hitherto supposed. 



♦ A. CunDingham in Ann. J[at. Hist. iii. (1839) 249. 



t S. Endlicher, Gen. PI. 1103 (1840). 



t S. Endlicher, Gen. PI. >Suppl. ir. pt. 3, 18 (1850). 



