THE RECEPTACULAR TUBE. 



95 



ferentiated from blades in this class than in Dicotyledons, 

 the inferior ovarj may be due to the combination of the pistil 

 with the united sheath-like portion of the perianth, which is 

 prolonged above the summit of the ovary just as it is in 

 Fuchsia, though it is not so prolonged in the Snowdrop. 



Anatomy of the Receptacular Tube.— Tracing the course 

 of the fibro-vascular cords from the pedicel below the flower, 

 say of Prunus Lauro-cerasus, the common laurel, there will be 

 found to be ten, corresponding to the sepals and petals. 

 The cortical tissue and epidermis are continuous throughout, 

 from the pedicel to the summit of the tube. It is well seen 

 also in the tapering end of a pear, from which the cortex 

 gradually widens, while the fibro-vascular cords run verti- 

 cally up the middle. Before the cords arrive at the border 

 of the free tube of the Laurel, they have given rise to the 

 staminal cords by chorisis, as shown in Fig. 28, a, h. Fig. a 



sti sL-j^iJ 



str 



^'St.JS 



Fig 28. — Receptacular tube of Prunus (after Van Tieghem). 



represents a section near the edge of the tube in which both 

 the sepaline (s) and the petaline (^) have given rise by tan- 

 gential chorisis to a whorl of stamens {st. 1) ; but the petaline 

 by radial chorisis to another whorl {st. 2), i.e. to twenty 

 stamens in all. Fig. h represents a vertical view of the same.* 



* The single carpel is represented in Fig. a to show the position of 

 its three cords, one being dorsal, and the other two marginal. 



