368 MULTIPLICATION. 



ceous condition of the carpel, in which the margins 

 are disunited. In such cases the ovules may occupy 

 the margin or may be placed a short distance within it, 

 as in the case of some open carpels of Ranunculus 

 Ficariay^ and in which two ovules were borne in shallow 

 depressions on the upper or inner surface of the open 

 carpel and supplied with vascular cords from the cen- 

 tral bundle or midrib. The outer coating of the ovule 

 here contained barred or spiral fusiform vessels derived 

 from the source just indicated. 



In the very common cases where the pistil of Tri- 

 folium repens becomes foliaceous (see Frondescence), 

 the outer ovules are generally two or more instead. of 

 being solitary. So, also, in the Rose with polliniferous 

 ovules (see p. 274). Among Umbelliferce affected with 

 frondescence of the pistil a similar increase in the 

 number of ovules takes place. It will be borne in 

 mind that in most, if not all, these cases the structure 

 of the ovule is itself imperfect.^ 



What are caUed in popular parlance double almonds 

 or double nuts (Gorylus) are cases where two seeds ai'e 

 developed in place of one. 



In the * Revue Horticole,' 1867, p. 382, mention is 

 made of a bush which produces these double nuts each 

 year in fact, it never produces any single-seeded fruit. 

 The plant was a chance seedling, perhaps itself the 

 offspring of a double-seeded parent. It would be inter- 

 esting to observe if the character be retained by the 

 original plant, and whether it can be perpetuated by 

 seed or by grafting. 



It is necessary to distinguish in the case of the nut 

 between additional seeds or ovules, as just described, 

 and the double, triple, or fourfold nuts that are occa- 

 sionally met with, and which are the result either of 

 actual multiplication of the carpels or of the continued 

 development of some of the carpels which, under ordi- 



' Seemann's ' Journal of Botany,' 1867, vol. v, p. 158. 

 ' Cramer, ' Bildungsabweich,' p. QQ, Astrantia major, Eryngium, to 

 which may be added Vaucus, Heraclenm. &c. 



