68 REPRODUCTIVE ORGANS. CHAP. III. 



Mono- The monophyllous calyx, which is exemplified 

 p y us * in the Primrose, is generally regarded as consisting 

 of three parts the tube, the mouth, and the 

 border. The tube is the lower and somewhat cy- 

 lindrical part; the mouth is the upper extremity 

 of the tube ; and the border is the part which ex- 

 tends beyond the mouth of the tube, sometimes 

 entire, as in Matthiola scabra, and sometimes di- 

 vided into segments, in which case it is in some 

 species cleft down to the middle, as in the Rose ; 

 in others it is cleft down almost to the base, as in 

 the Lime-tree ; and in others it is divided into an 

 under and upper segment, suggesting the idea of 

 lips, and characterized by the term labiate, as in 

 the genus Thymus. 



Polyphyl- The proper and polyphyllous calyx is either 

 single or double. It is single if it consists of only 

 one set of distinct pieces, as in the genus Limim ; 

 double if it consists of two distinct sets, the one 

 enveloping the other, as in the Common Mallow. 



In some plants the proper calyx is thin and 

 membranaceous, as in Convolvulus sepium ; in 

 others it is thick and fleshy, as in the Rose. Its 

 figure is cylindrical, as in the Pink ; or prism- 

 shaped, as in Pulmonaria ; or bell shaped as in 

 Convolvulus ; or pitcher-shaped, as in the Rose ; 

 or it is inflated, being merely distended in the 

 middle, but contracted at the extremities, as in 

 the genus Silcne or Catch-fly, 



