FLOWERS. 45 



The disk (Plates IV. and V., d) is absent in some 

 flowers. It is commonly a fleshy or glandular body of a 

 yellow or greenish colour; sometimes inserted round the base 

 of the ovary, as in Plate IV.; sometimes in adhesion to and 

 above it, as in Plate V. ; and occasionally under the ovary. 



' The perigynous and epigynous insertions of the stamens 

 being easily confounded, the term calycifloral has been 

 given to all plants whose corolla (whether mono- or poly- 

 petalous) and stamens are inserted on the calyx, and this 

 whether the calyx be below the ovary, as in the apricot, or 

 above it, as in the Campanula, coriander, and madder. The 

 term thalamifloral has been given to plants whose poly- 

 petalous corolla and stamens are inserted below the pistil, 

 or hypogynous ; and corollifloral, to plants with a mono- 

 petalous staminiferous corolla inserted below the pistil, 

 or hypogynous, as in the primroses.' 



— Le Maout and Decaisne. 



The ovary contains the ovules 1 or seed-germs. It is 

 formed either of one bladder-shaped piece, or of several 

 pieces joined at the edges, the junction being the suture 

 (shown in fig. E in Lesson on ' Seeds,' p. 5). Each piece is a 

 valve. The ovary has one or more cells, each containing 

 one or more seed-germs, fixed to the placenta or inner part 

 of the ovary by the funiculus (cord) in the manner 

 described in Lesson I. The placenta has a direct com- 

 munication with the tube of the pistil for the purpose of 

 fertilizing the seed-germs, without which process they could 

 not become perfect seeds. Some flowers are without a pistil. 



The perianth is the envelope which surrounds the flower ; 

 but this term is more frequently used when the calyx is 



1 Ovule, a little egg. 



