ORGANS OF EEPEODUCTION. 



221 



sacs, when they are termed gihhous or saccate. If the calj'x has 

 one or more tubular prolongations downwards, it is said to be 

 calcarate or spurred. Only one spur may be present, as in the 

 Indian Cress ( Tropceolum) {fig. 452), where the spur is formed 

 by three sepals, or in the Larkspur, where it is formed by one ; 

 or each of the sepals may be spurred, as in the Columbine {Aqui- 

 legia) {fig. 453). In the Pelargonium, the spur instead of being 

 free from the pedicel, as in the above instances, is united to it. 



On the outside of the calyx of some 

 flowers, as in those of many plants of the 

 Mallow (/^. 454), Pink {fig. 458), and 

 Eose orders {fig. 439), there is placed a 

 whorl of leaf-like organs which is con- 

 sidered by some botanists as an outer calyx, 

 and to which the name of epicalyx has 

 been accordingly given, but this outer whorl 

 is evidently of the same nature as the in- 

 volucre already noticed (see page 182). 



The duration of the calyx varies in 

 different flowers. Thus it is caducous or 

 fugacious, when it falls off as the flower 

 expands, as in the Poppy {fig. 455). In 

 the Eschscholtzia the caducous calj-x 

 separates from the hollow thalamus to 

 which it is articulated, in the form of a 

 funnel, or the extinguisher of a candle, 

 separation of the calyx occurs in the Eucalyptus, except that 

 here the part which is left behind after the separation of 



Fig. 434. Calj-x of Bi- 

 bisciis surrounded by 

 an epir.alyx or invo- 

 lucre. 



A somewhat similar 



Fig. 455. 



Fig. 456. 



Fig. 457. 



Fig. 455. Flower of Poppy, showing a caducous calyx. Fig. 4.56. Accres- 

 cent calyx of the Winter Cherry (,Physalis Alkekoigi). Fig. 457. Ver- 

 tical section of the fruit of the Quince (Ci/donia vulgaris), showing the 

 tube of the calyx adherent to the ovary, and its limb foliaceous. 



