Dr Dickson on Diplostemonous Floivers, d:c. 259 



In constructing those diagrams which illustrate arrange- 

 ments in the Malvaceae (figs. 5, 6, 7, and 8), having found 

 great difficulty in giving diagrammatic expression to the 

 staminal groups, I* have represented the said groups by 

 symbols of infinity, which conveniently enough indicate the 

 indefinite number of the staminal lobes. 



Explanation of Plate III. 

 [Figs. 1-13 are from my own designs. Figs. 14 and 15 are taken from 

 Payer's "Organogenic," plate xiii. figs. 28 and 32. The diagrams are con- 

 structed with the utmost conventional uniformity, being merely intended 

 to represent the position of the parts, not their /om. In the diagrams, the 

 posterior aspect of the flower is above, the anterior below, and the stamens 

 are numbered in the order of their appearance.] 



Fig. 1. Arrangement in Geranium, Malachium, &c. Younger (accessory) sta- 

 mens external. Carpels alternate with older (primary) stamens. 



Fig. 2. Arrangement in Coriaria, Agrostemma, Cerastium, &c. Younger sta- 

 mens internal, probably forming a genuine whorl. Carpels alter- 

 nate with the younger stamens. 



Fig. 3. Arrangement in Lasiopetalum corylifolium, and probably in Biittneria, 

 Melochia, &c. Outer and older stamens fertile, and superposed to 

 the petals ; inner and younger sterile, and alternate with the outer. 

 Carpels, as in fig. 2, alternate with the younger (sterile) stamens. 



Fig. 4. Isostemonous arrangement in Hermannia. Fertile stamens, as in the 

 last, superposed to the petals. The carpels are superposed to the 

 sepals, apparently replacing the staminodes of the last form. 



Fig. 6. Arrangement in Hibiscus, Pariiium, and Lagunea. Same as last form, 

 except that, instead of five simple stamens, there are five staminal 

 groups (indicated by symbols of infinity). 



Fig. 6. Arrangement in Malope. Same as last, except that, instead of five 

 simple carpels, there are five carpellary groups. 



Fig. 7. Arrangement in Pavonia Typhalea, P. begonicefolia, P. odorata, P. um- 

 bellata, and P. zeylanica. Staminal groups as in figs. 5 and 6, super- 

 posed to the petals. Ten carpels ; five fertile, superposed to the 

 sepals, and five sterile, superposed to the petals. The sterile carpels 

 are indicated by small circles alternate with the loculi. 



Fig. 8. Arrangement in Malvaviscus, Urena, Pavonia sp. {hastata?). Same as 

 last form, except that those carpels which are sterile there, are 

 fertile here, and vice versd. 



Fig. 9. Arrangement in Polygala, as described in the text. 



Fig. 10. Arrangement in Cardiospermum, as described in the text. The sepals 

 are numbered in the order of their appearance. Sepals 3 and 5 

 become connate, and the petal (indicated in outline) which alternates 

 with them aborts. If an oblique line be drawn, as in the diagram, 

 through sepal 4 and the abortive petal, the parts are arranged 

 symmetrically on either side of it. This imaginary line, by torsion 

 of the peduncle, becomes antero-posterior, the abortive petal be- 

 coming posterior (superior). See Payer's " Organogenic," p. 153. 



