390 SECTIONAL TRANSACTIONS.— K. 



In many instances carpel polymorphism appears to have arisen in association 

 with considerable reduction in carpel number, as in Rosacese (Potentilla-Rosa types v. 

 other sections of the family), Phytolaccacese {Phytolacca- Ercilla types v. Rivineoe), 

 Ranunculacese (Anemone-Clematis types v. Nigella), Alisma v. Butomus. 



In some cases reduction has resulted in the utilisation of persisting elements of 

 those members which are suppressed in the construction of those which survive ; 

 these latter might therefore be said to arise by a process akin to synthesis. 



Transition from one carpel form to another may occur in aUied forms [Capsella 

 Bursa-pastoris and C. Heegeri, Triglochin maritimum and T. paluslris, certain species of 

 Oxalis, the median carpel pair in 2-valved and 4-valved ovaries of the Cruciferse. 



The conception of carpel polymorphism as outlined above 



(a) Satisfactorily explains the whole series of anomalies in the pistil of the 

 Cruciferse. 



(6) Accounts for the commissural stigma in general. 



(c) Affords a rational explanation of obdiplostemony. 



{d) Throws a new Ught on parietal, free-central, superficial and axile placentation, 

 and on loculicidal dehiscence. 



(e) Shows that the anomalies of the solitary terminal carpel, the gynobasic and 

 the supernumerary style and the false septum are not realities. 



(/) Renders intelhgible the infertility of the female organ in the male flowers of 

 many diclinous species. 



Dr. R. Marloth. — The Nomenclature and Chemistry of Euphorbia virosa. 



Dr. T. R. Sim. — New South African Trees and Shrubs. 



Prof. P. A. VAN DER Byl. — Descriptions of Some Previously Unnamed 

 South African Fungi. 



Mr. R. Davies. — The Growth and Development of Peaches. 



Dr. and Mrs. I. B. Pole Evans. — Scenes of South African Vegetation. 



Dr. L. Verwoerd and Mr. B. J. Ditfenaab..— Descriptions of New and of 

 Unrecorded Species of South Afi icon Fungi. 



Afternoon. 

 Excursion to Muizenberg. 



Saturday, July 27. 



Excursion to Table Mountain. 



JOHANNESBURG. 



Wednesday, July 31. 



Prof. C. E. Moss. — Vegetation of South Africa, with Special Reference to 

 the Witwatersrand District. 



Miss D. Weintroub." — The Aquatic and Sub-aquatic Vegetation and Flora 

 of the Witivatersrand District. 



The area investigated extends from Florida, nine miles west of Johannesburg, 

 to Brakpan, twenty-three miles east of this city. 



The sheets of water maj' be classified as follows : — 



(1) Artificial dams, usually in connection with the gold mines, and, as a rule, of 

 little botanical interest. 



(2) Semi-natural lakes, made by the artificial damming up of natural streams. 

 Florida Lake is the best known. Reed swamps occur, with the following plants 



