98 THE STRUCTURE OF FLOWERS. 



These cords of the inner whorls may be given off at the 

 terminal point of the pedicel; that is, at the base of the flower. 

 In this case they may all run parallel from the base to the 

 summit of the receptacular tube ; or they may branch at 

 various heights within the tube itself, as in Prunus, described 

 above ; or, lastly, they may not arise until the summit of the 

 ovary is reached, when they pass off and enter their respective 

 floral organs directly. These variations occur in both free 

 receptacular tubes as well as when coherent to ovaries. 



As an example of the first case may be mentioned Alstroe- 

 meria versicolor; of the second, Galanthus nivalis, or Snowdrop; 

 and of the third. Narcissus. In Alstroemeria, all the floral 

 appendages have their cords distinct and independent, but 

 invaginated by the tube of parenchyma throughout (Fig. 30). 

 In the Snowdrop, the carpellary cords are distinct, but the 

 perianth and androecium are inserted in the pedicel by a single 

 verticil of cords, which becomes double higher up. Lastly, in 

 Narcissus, all the parts of the flower are originally inserted 

 in the pedicel by six cords, of which three give rise by 

 successive tangential fission to a radial series composed of 

 the dorsal cords of the carpels, the stamens opposite to the 

 sepals, and the sepals themselves. Similarly, the other three 

 form the petals together with the whorl of stamens opposite 

 to them.* 



In GaTTipanula, and to some extent in Lobelia, the cords 



* Ph. Van Tieghem, to whose researches I am indebted for the above, 

 but which I have also paralleled in other cases, represents them neatly by 

 the following formulas, wherein ( ) signifies vascular union, and [ ] the 

 cellular union of the receptacular tube ; while (d) stands for the dorsal 

 and (m) the marginal cords of the carpels. Stp signifies petaline and 

 St. sepaline stamens. 



Alstroemeria— IS S + 3 P + 3 St, + 3 Stp + 3 CJ. 



Galanthus— IS (S +.St,) + 3 (P + Stp) + 3 CJ. 



Narcissus— [_S (S + St, + d C,) + 3 (P + Stp) + 3 CJ. 



