MOEPHOLOGY OF EEPRODUCTIVE OEGANS 153 



the observer to distinguish the primary from the secondary 

 divisions. When a gamosepalous calyx is entire, the number 

 of sepals can then be ascertained by the venation, as the 

 principal veins from which the others diverge generally oorre- 



FiG. 287. 



Fig. 288. 



Fig. 280. 



Fi'i. 287. Partite inferior calyx of the Pimpernel (Ana^jaUU). Fiff. 2S8. 



IJreeolate calyx of the Heabane (Ilyoscyamus). Fkt. 289. Bilabmte 



calyx of the Dead-nettle (La?iiium j. 



Fig. 290. 



spond to the midribs of the component sepals. In a gamo- 

 sepalous calyx in which the union exists in a marked degree, 

 the part where the sepals are united is called the tube, the free 

 portion the limb, and the orifice of the tube the throat ot faux 

 {figs. 288 and 289). 



If the union between the sepals is unequal, or the parts are 

 of different sizes, or of irre- 

 gular figures or forms, the 

 calyx is said to be irregular 

 (fi^. 289) ; if, on the con- 

 trary, the parts are alike in 

 figure and form, of the same 

 size, and united so as to 

 form a symmetrical body, 

 it is regular (fig. 288). 

 Some varieties of the irre- 

 gular and also of the re- 

 gular calyx have received 

 special names. Thus in the 

 Dead-nettle (fig. 289), the 

 irregular calyx is said to be 

 labiate, bilabiate, or lipped, because the five sepals of which 

 it is composed are united in such a manner as to form two 

 lips. Of the regular forms of the gamosepalous calyx a number 

 are distinguished under the names of tubular, bell-shaped or 



Fie/. 290. Vertical section of the flower of the 

 Myrtle (Myrtus communis), cat. Tube of the 

 calyx adherent to the ovary, o. s. Stamens. 



