REJUVENESCENCE IN NATURE. 93 



in the transition from calyx to corolla, is a very frequent 

 phenomenon in the transition from the corolla to the 

 stamen-formation. As the hypsophyllary formation is 

 not unfrequently cut off from the euphyllary region by 

 sinking down even to the suppression of the leaf- forma- 

 tion, so we see the stamen-formation frequently cut off 

 similarly by a region of suppression, from the preceding 

 formation. It is often difficult to decide here whether 

 the parts subject to abortion, which may occupy one or 

 more circles, are to be regarded as suppressed inner 

 petals or suppressed stamens. As imperfectly developed 

 leaves, they are, looked at by themselves, neither one nor 

 the other ; but comparative examination shows that the 

 abortive circles are certainly to be attributed sometimes 

 to one and sometimes to the other side, and in this sense 

 are to be regarded sometimes as inner circles of the 

 corolla, and sometimes as outer circles of stamens. Thus 

 in the Primulaceee for example, we have reason to con- 

 sider the abortive circle as an inner corolline circle, since 

 the corresponding circle of the flower is developed in 

 some of the genera of the allied family of the Myrsineae 

 (e.g., Jacquinid), as also in many of the genera of the 

 likewise related Sapoteae, actually in the form of an 

 inner corolla, never in the form of a circle of stamens. 

 The same holds of the Ericaceae, in which I have seen 

 the abortive circle developed abnormally, in Erica 

 baccans, as an inner corolla. The same occurs in the 

 Jasmineae, for some of the species of jasmine exhibit 

 an inner corolla almost normally. In the Oxalideae and 

 Geraniaceae we must also assume an abortive inner 

 corolla, the traces of which exist in the form of glands or 

 little scales. In abnormal flowers of Pelargonium, I have 

 often found some of the organs actually developed into 

 the form of petals. That the abortive circle of the 

 Geraniaceae is to be regarded as an inner corolla, is still 

 more distinctly proved by the mode of arrangement of 

 the parts of the flower in the genus Monsonia, belonging 

 to this order. Monsonia possesses not merely two, but 



