238 



BOTANY OF THE LIVING PLANT 



Fig. i86. 

 ^^e^tical section of flower of the Peach, as 

 an example of a perigynous flower. (After 

 Figuier.) 



and petals. In the Caper Family the carpels alone are raised thus 



on an elongated axis. More frequently there may be a local widening 



out of the receptacle, in the form of a ring or cup, by growth of tissue 



beneath the insertion of the lower 

 parts. The sepals, petals, and sta- 

 mens may together be carried out- 

 wards upon its margin, while the 

 gynoecium occupies the centre of 

 the cup. This occurs frequently in 

 certain families, and is well seen in 

 the Rosaceae (Fig. 1 86, Peach). 

 Occasionally an isolated genus shows 

 it, as in Subidaria, among the hy- 

 pogynous Cruciferae. It may be 



regarded as a local modification of the hypogynous state, and is 



described as perigynous. 



A more important modification is that which leads to the sinking 



of the gynoecium downwards into tlie tissue of 



the abbreviated axis. This gives the epigynous 



condition, with so-called inferior ovary (Fig. 187, 



Fuchsia). The way in whicli this comes about 



is best illustrated by observing the development 



of a flower of an epigynous type, as may be 



easily done in tlie Sunflower or others of the 



Compositae (Fig. 188). 



If median sections be cut of a young liead of Sun- 

 flower, the general receptacle will be seen to bear 

 flowers of different ages, the oldest at the outside and 

 the youngest nearest the centre. Each arises in the 

 axil of a bract, and the youngest may have the lorni 

 of a simple convex papilla (i.). But as the growth at 

 the centre is slower than at the periphery, the flower 

 becomes first flattened and then hollowed. Five 

 rounded bosses appear on the margin of cup, which 

 are the five petals (ii.). The hollow surrounded by 

 them deepens, and five other bosses appear internally 

 to, and alternating with them. These are the staitiois 

 (iii.). By their formation the hollow is narrowed, 

 and presently from its shoulders two other upgrowths 

 are formed. These are the carpels (iv.). Meanwhile 

 t\\'o small outgrowths may be seen at the outside, 

 which previously was smooth. These are two teeth representing the reduced 

 calyx, which thus appears delayed out of the normal succession. The carpels 

 are in contact above, and enclose a cavity, which is the ovarian ca\dty, 



Fig. 18;. 

 Vertical section of flower 

 of the Fuchsia, as an ex- 

 ample of an epigynous flower. 

 (.\fter Figiiier.) 



