286 MR. A. S. HOEXE— A COl^TEIBUTION TO 



writer finds no bilocular ovaries in his material of G. lucida. The ovular mamelon 

 grows downwards and develops into an ovule of the abaxial type. The orientation in 

 bilocular ovaries has, of course, not been observed. The nucellus, which is com- 

 paratively long, is of very small bulk — a median section shows three rows of cells within 

 the nucellar epidermis ; it is invested by a single integument (PL 29. figs. 75, 76). 



Vascular Structure. 



Serial sections of the flowers of both G. lucida and G. liltoralis were prepared. In 

 G. lucida six or seven bundles were present at the base of the ovary (Text-fig. 11, A). 

 These branch to form a single series, consistino: of a variable number of bundles 



>> 



twelve or more — in the ovary-w^all (B-P). Some of the smaller bundles extend inward, 

 and in the neighbourhood of the placenta anastomose, presenting in thick sections the 

 appearance of an incomplete vascular collar (E-I) ; from this " collar "as many as five 

 separate bundles, of which three {ov 1, ov 2, ov 3) are shown (F), extend into the 

 '* placenta" and unite there to form the single ovular bundle. Since the petals and 

 stamens are absent in this species, there are no outgoing branches to these organs, 

 and all the principal bundles, together with a few which proceed from the " collar, 

 extend into the basal portion of the style (I, J), diminishing in number until only a 

 few remain. The vascular structure is similar in G, littoralis (petals present), except 

 that the bundles are more numerous^ — nine at the base of the loculus and sixteen 

 higher up in one specimen. 



The vascular structure in the neighbourhood of the placenta recalls the somewhat 

 similar collar-like arrangement of vascular tissue in the reduced unilocular ovary of 

 Corohia. In Griselinia, however, branches from every part of the ovary -wall contribute 

 to the bundles entering the " placenta." 



Nature of the Ovary. 



Baillon considered the ovary of Griselinia to be incompletely tricarpellary, the body 

 of the ovary consisting of the lower portion of one carpel. But the peculiar vascular 

 structure justifies a modification of this view. When we consider the cases already 

 discussed, it is found that where the terminal ovule is by origin axially situated the 

 vascular tissue presents an anomaly, but w^here it is parietally situated by origin the 

 conditions are not the same and the vascular tissue need not necessarily be diverted 

 from the normal course. Thus, in Viburnum, the ovary was primitively septate, but, 

 owing to the loss of the septa, the vascular tissue that had originally an axial extension 

 became diverted to a peripheral position. Again, in Gorokia, where in bilocular forms 

 the ovules are suspended from the septum, the absence of a loculus disturbs the normal 

 disposition of the vascular tissue in relation to the ovule. But in Aucuha, also originally 

 septate, where the ovule is suspended from a parietal placenta and comparable to the 

 parietally situated ovules in the Combretacese, no vascular anomaly exists in relation 

 to the position occupied by the ovule. Now, in Griselinia, the placenta is abnormally 

 large, and the numerous branches contributinor to the ovular trace arise from bundles 



