108 



MORPHOLOGY, OR COMPARATIVE ANATOMY. 



proper. An investigation of the course of development will show the 

 difference between the two, and, generally speaking, the position of the 

 petals and stamens ; if the latter are perigynous, it is probable that the 

 tube below is receptacular. The venation and internal structure will also 

 serve as guides in this matter, inasmuch as the receptacular tube contains 

 not only its own vascular bundles, but those of two or more verticils of 

 flowers, and which are derived from the primary ones by subdivision. 



Form, The gamosepalous calyx is subject to the same kinds of 

 modification as that in which the sepals are distinct. It is either 

 regular or irregular. 



Of the regular kinds we find a large number which present forms ad- 

 mitting of general technical names, such as tubular or cylindrical, cup- 

 shaped, infundibuliform or funnel-shaped, campanulate or bell-shaped, 

 urceolate when the tubular form is expanded below, turbinate or top- 

 shaped when expanded above, inflated when the lateral view is oval or 

 roundish with a narrow mouth (fig. 180), &c. In some species of Cam- 

 panula there are regular appendages at the bottom of the sinuses between 

 the teeth. In Primula and some other genera the tubular calyx is an- 

 gular or plaited. 



Calyces nearly resembling the above are rendered irregular either by a 

 greater extent of disunion taking place between some of the sepals, the 

 intervening fissures being so much deeper than the others that the teeth 

 become associated in two sets, giving a bilabiate condition (fig. 181) or 

 by irregularities at the base, where a shallow pouch renders the calyx 

 gibbous (fig. 178), a deeper one saccate, and a long narrow pouch forms 

 what is called a spur. In Pelargonium this spur adheres to the peduncle. 



In some instances a tubular development of the receptacle or fiower- 

 stalk simulates the spur of the calyx. 



Fte. 184. 



Fig. 181. 



Fig. 183. 



Fig. 181. Bilabiate calyx of Salvia. 



Fig. 1S2. Floret of Kcabiosa, the limb of the calyx replaced by bristles (pappus). 



Fig. 183. Fruit of Cichorium, crowned by the persistent calyx represented by a circle of spines 



(pappus). 

 Fig. 184. Section of the persistent calyx, enclosing the ripe capsule, of Hyoscyamus. 



The Pappus. The free portion of the calyx of Com posits, Dip- 

 sacese, and Valeriauaceae exhibits a very aberrant condition by 

 appearing in the form of scales, bristles, or feathery or simple 



