ANGIOSPERMS. 



385 



3. Basal or axillary, springing from the base of the upper side of the carpel 

 or from the axil of the carpel, as in Raminculus, Sedum, Zannchiellia 

 according to Warming ^ 



//. Ovules borne on the axis and si)ringing from the prolongation of the floral 

 axis within the ovary, the carpels themselves being sterile ; these are 



4. Lateral, when they arise beside or below the apex of the axis which either 



rises as a column and bears numerous ovules, as in Fig. 309, or ceases to 

 grow after forming one ovule, so that this may appear to be terminal, as in 

 Fig. 310. 



5. Terminal, when the apex of the axis itself becomes the nuccllus, as in Fig. 



308, the Piperaceae, Naias, etc. 



The question, to which of these types the ovules of any given plant belong, must 

 be decided in each individual case, but the ovules that are marginal on the carpels are 

 much the most common in Angiosperms, while the superficial and the axillary 

 positions are confined to single families or genera. If we compare the position of the 

 ovules in Angiosperms and Gymnosperms, we find that the ovules of the Cycadeae 

 belong to the marginal class, those of Dammara and Araucaria to the superficial, 

 those of the Cupressineae to 

 the axillary ; those of Giiigko 

 are lateral upon the axis, those 

 of Taxzts are terminal. Similar 

 varieties of position are found 

 in the sporangia of the Vascular 

 Cryptogams, though none are 

 terminal upon the axis ; the 

 sporangia of Ophioglossum, for 

 example, are produced latt^rally 

 on a leaf, those of many Ferns 

 are superficial on a leaf, those 

 of Lycopoditim and Selaginella 

 are axillary or basal; the 

 latter may also be considered 

 as being upon the axis and 

 lateral, of which kind the 

 sporangia of the Psilotaceae must be regaided as the most striking examples. 



The ovules are sometimes rudimentary; those of the Balanophoreae and 

 Santalaceae have no integuments, the nucellus being naked and in many species 

 consisting of only a few cells. The same is the case with the Loranthaceae ^ where 

 the ovules are produced, as in the Santalaceae, from an axial placenta ; but the latter 

 becomes so closely united at a very early period with the tissue of the carpel, that 

 when the flower opens it is no longer possible to distinguish the ovules by any 



riG. 318. Funkia cordata. 

 ovary ; two ovules SK are visit 

 margins of the carpels, g vascular bundles surroun 

 C young ovule in optical longitud 



•integument. ^ is slightly. C is very highly i 

 is the mother-cell of the embryo-sac. 



' Warming, Recherches sur la ramification des Phanerogames, Kopenhagen, iS;:;, page x.xii, 

 Taf. xi, Fig. 1-10. Axillary ovules are as little to be regarded as shoots (stems) as are tlie axillary 

 sporangia of the Lycopodieae and Selaginelleae ; and there is as little ground for regarding mar- 

 ginal ovules a^ leaf-tips or pinnae. 



^ Treub, Observations sur les Loraiithacecs ^Ann. du jard. liot. de Buitenzorg. 18S1 . 

 f2] 



