112 Mr. B. Clarke on Columelliacese. 



less sinuous), their curvature then would be towards its centre, 

 as in Columellia (fig. 20), so that the resemblance between them 

 is so close as to show that Cucurbitacese approach the Mono- 

 petalous series of natural orders more by this peculiarity of their 

 anthers than by any other parts of their structure*. 



While, however, the anthers of Columelliacese are so identical 

 with those of the Cucurbitacese as to suggest a very near affinity 

 with that family, their nearest affinity, as regards their relation 

 to the Monopetalse, is most probably with the Stylidiacese, be- 

 tween which and Scsevolese may be their true station. With 

 Stylidiacese they a^ree in the number of the lobes of the corolla 

 being variable, while the stamens remain two, the carpels in 

 both being anterior and posterior, and the stamens right and 

 left, which in Stylidiacese becomes obvious by tracing the fila- 

 ments down to their origin ; the only apparent difference con- 

 sisting in the stamens of Stylidiacese adhering to the style in- 

 stead of to the corolla, and in the anther-lobes not being sinuous ; 

 but when it is recollected that these differences may occur 

 among the genera of the same family, as in Cucurbitacese (so 

 far as that the stamens are either entirely distinct and separated 

 from each other, or form a monadelphous bundle in the centre 

 of the flower), their approach must be very close. 



EXPLANATION OF PLATE VL 



Fig. 1. A young fruit of Myrica quercifolia seen from above, the two 

 stigmas remaining attached. 



Figs. 2, 3 & 4. Transverse sections of it, showing the relations of the 

 stigmas to the internal structure of the ovary ; viz. that they are 

 opposite shallow depressions in the cavity, which are continued 

 by distinctly marked lines to the thin cellular epicarp. Fig. 4. 

 Section near the base. 



Fig. 5. A young fruit of M. quercifolia, having three stigmas, seen from 

 above. 



Figs. 6 &c 7- Transverse sections of it, showing the relation of the stigmas 

 to the internal structure of the ovary, and that it consists of three 

 nearly equal carpels united by their margins, the tendency to 

 dehiscence being at the dorsal sutures. Fig. /• Section near the 

 base. 



Fig. 8. A female flower of Cannabis sativa, showing the adherent calyx : 

 a, the posterior side. 



Fig. 9. A male flower of Platanus orientalis, artificially expanded to show 

 the sepals ; beneath the filaments are seen scale-like bractese. 



Fig. 10. One of the bractese of the male flower. 



Fig. 11. A female flower of the same, showing the calyx and barren sta- 

 mens or petaloid bodies, alternating with the sepals. 



* The affinity of Cucurbitacese to Campanulaceae has been traced by 

 Auguste de St. Hilaire from other characters ; they may, however, be nearer 

 Lobehaceae than to that family, on account of the occurrence of unisexuality 

 in the latter, and also of the union of their anthers. 



