CALYCIFLOE.E. 273 



ILLUSTRATIVE GENERA. 



Series 1. PLAGIOSPERMEJE. Ovules 

 horizontal. 



Feuillsoa, L. 

 Bryonia, L. 

 Citrullus, Neck. 

 Ecbalium, L. C. Rich. 

 Momordica, L. 

 Cucumis, L. 

 Cucurbita, L. 



Series 2. ORTHOSPERMEJE. Ovules 

 erect or ascending. 



Trianosperma. 

 Elaterium. 



Series 3. CREMOSPERME^E. Ovules 

 pendulous. 



Sicyos, L. 

 Sechium, P. Br. 



Affinities, &c. The Cucurbitaceae, divided as above into 3 series, are 

 still further divided bv Hooker into 8 tribes according- to the number of 

 the stamens, the form ot the anthers, the nature of the placentas, and the 

 number of the ovules, &c. They form a very well-defined Order, but 

 have affinities of a very diversified range. The habit and the placenta- 

 tion ally them closely with Passifloracese, from which they differ, how- 

 ever, in the position of the ovary, the unisexual flowers, the peculiar 

 structure of the anthers, and the want of perisperm. Their nearest rela- 

 tions among the epigynous Orders, after Begoniaceae, appear to be the 

 Loasaceee, through Gronovia, which agrees in its climbing habit, and 

 comes near the Sicyece. In the structure of the ovary and seeds and the 

 position of the stamens there is a certain approach to the polypetalous 

 Onagraceae, Myrtaceae, &c., and, further, to the monopetalous Oainpanu- 

 laceae. Again, the diclinous condition and the structure of the ovary 

 connect them with Papayacese. This Order presents a number of points 

 of interest as regards structure. The tendrils appear here to be partially 

 metamorphosed leaves, while their base is constituted of an abortive 

 branch ; but they have been referred by various botanists to leaves, sti- 

 pules, peduncles, branches, and even roots. Their position by the side of 

 the leaf is very curious, and accords with Warming's suggestion that the 

 tendril is an extra-axillary branch, arising as it does from a flat cellular 

 outgrowth outside the leaf-axil. Warming also describes the following 

 structures as emerging from the axil of the leaf in many Cucurbits : 1. 

 A terminal 3 or nower ; 2. A leaf-bud j 3. An inflorescence homo- 

 dromous with the principal axis, antidromous with the leaf-bud. In 

 Thladiantlia dubia, according to Dutailly. the tendril and the male flower 

 replace one another morphologically, being never found together, but the 

 one always in the place of the other. The andrcecium of these plants has 

 been considered to consist of five stamens, with unilocular anthers, united 

 into three parcels ; but by others it is asserted that these plants have 

 three stamens, two with two-celled anthers, and one with a one-celled 

 anther. Traces of the abortive stamens may, however, be detected in the 

 vascular bundles, so that the typical structure of the androecium is pent- 

 amerous. The construction of the ovary of the Cucurbiteee is remarkable, 

 the sides of the carpels being inflected to the centre, and then rolled in 

 further upon themselves until the marginal placentas are brought back 

 nearly to the circumference of the fruit ; hence, although termed parietal 

 placentas, they are rather an excessive case of the inflexion which ordi- 

 narily produces axile placentas. The form of the fruit is varied : the pepo 

 assumes almost every modification of globular, oval, bottle-shaped, sausage- 



