ORGANS OF REPRODUCTION. 



Fig. 457. Fig. 458. Fig. 459. 



229 



Fig. 457. Flower of Poppy, showing a caducous calyx. Fig. 458. Ac- 

 crescent calyx of the Winter Cherry {Fhysalis Alkekengi).- Fig. 



459. Vertical section of the fruit of the Quince {Cydonia vulgaris), 

 showing the tube of the calyx adJierent to the ovary, and its limb 

 foliaceous. 



lated, in the form of a funnel, or the extinguisher of a candle. 

 A somewhat similar separation of the calyx occurs in the 

 Eucalyptus, except that here the part which is left behind after 

 the separation of the upper portion, evidently belongs to the 

 calyx, instead of the thalamus as in the former instance. Such 

 a calyx is said to be cahjptrate or operculate. When the calyx 

 falls off about the same time as the corolla, as in the Crowfoot or 

 Buttercup, it is called deciduous. In other cases it remains after 

 the flowering is over, as in the Henbane {Jig. 446), Mallow, &c. 

 AVhen the calyx is adherent or superior it is necessarily per- 

 sistent, and forms a part of the fruit, as in the Quince (fig. 459), 

 Apple, Pear, Gooseberry, Melon,' Cucumber, &c. When it is 

 persistent and assumes a shrivelled or withered appearance, as 

 in the Campanulas, it is marcescent ; if it is persistent, and con- 

 tinues to grow after the flowering, so as to form a bladdery ex- 

 ])ansion round the fruit, as in the Winter Cherry, and other 

 species of Physalis {fg. 458), it is termed accrescent. 



2. THE COROLLA. 



The corolla is the inner envelope of the flower. It con- 

 sists of one or more whorls of leafy organs, called petals. 

 In a complete flower (^Jig. 421, p) it is situated between 

 the calyx and stamens, and is generally to be distinguished 

 from the former, as we have already seen, by its coloured 

 nature and more delicate structure. When there is but one 

 whorl of floral envelopes, as we have also before noticed, this is 

 to be considered as the calvx, and the flower is then termed 

 q3 



