THE STUDY OF THE EYOLUTIOIS" OF THE FLO WEE. 287 



exteucling in all parts of the ovary-wall, and appear to have been diverted from the 

 original disposition. Hence not only can we deduce that the ovary was primitively 

 septate, but also that the ovule was axially placed. 



Now, abortion, in Viburnum, originally tricarpellary, has conduced to the special 

 development of the body of one carpel, a fact that is evident from the asymmetrical 

 disposition of the vascular tissue in the flower and from the arrested loculi. But, in 

 Griselinia, as also in Corokia and Aucuba, the original course taken by the floral 

 vascular tissue does not appear to have been affected by abortion. Hence the conclusion 

 is reached that the septa disappeared without a special enlargement of the lower portion 



of any one carpel. 

 The writer's interpretation of the floral structure may be summarized briefly as 



follows : — The flower was primitively hermaphrodite, and became unisexual after the 



attainment of epigyny; it exhibits an apetalous tendency, definitely expressed in 



G. lucida, the ovary was originally tricarpellary and trilocular, and the loculi, by 



analogy with the Caprifoliacese, were at first pluriovulate. Subsequent abortion resulted 



in the disappearance of the septa, but did not induce the special enlargement of the 



lower portion of any one carpel, as in Viburnum; concurrently, the ovules were 



numerically reduced to one, the equivalent of an axially suspended ovule in the 



primitive ovary. If Baker's record of bi- and trilocular ovaries in Melanophylla be 



correct, we may conceive that Griselitiia has proceeded a stage further than Melano- 



the direction of aborti 



Nyssa. 



Morphology of the Floioer and Ovule. 

 The flowers of Nussa are hermaphrodite or unisexual. The male flowers consist of 



Accordim^ 



sepals, petals, and stamens, which vary from five to an indefinite number. 

 Bentham and Hooker *, ovarian rudiments are absent or a subulate process exists in the 

 centre of the disc. The female flowers consist of an inferior ovary surmounted by a 

 calyx— petals are absent or minute and there are no rudiments of stamens— and 



minated by 



tyles. The flowers of N. sylvatica, growing at Kew, which 



the writer examined, proved to be either hermaphrodite or female. The hermaphrodite 

 flowers possessed one, two, or three stamens, so that a complete series existed between 



the two kinds. 



Bentham and Hooker f state that the ovary is unilocular, but Baillon J records that 



it mav be sometimes bilocular. The writer has observed only unilocular ovaries in 

 N, sylcaUca, The ovule is terminal in mature ov^xries, but this is not strictly so in very 

 young flowers ; in one particular case measurements were made with 

 of sections, each -015 mm. thick; the height of the loculus was 0-24 mm. ; the total 

 Icncpth of the ovule 0-165 mm. The ovule was attached to the ovary-wall at a point 



the aid of 



• G. Bentham et J. D. Hooker, Gen. PI. i. (1857) 952, 



t G. Bentham et J. D. Hooker, I. c. t H. Baillon, ' Histoire dea Plantes,' yi. 267. 



SECOND SERIES. — BOTANY, VOL. VIII. 



2t7 



