ORGANS OF REPRODUCTION. 



211 



gyrate cyme. These cymes are especially developed in the Bo- 

 raginacese, as in the ^ox%Qi-ro.Q-not{Myosotispalnstris) {fig. 416), 

 and in the Comfrey {Symphytum) {fig. 416a). In these plants 



Fig. 416a. 



Fig. 416a. Scorpioid cyme of Comfrey {Sijmpht/tum officinale). 



the leaves are alternate ; but such a cyme may also occur in 

 opposite-leaved plants, and the manner in which it is commonly 

 believed to be formed in the two cases, is as follows : — Thus, in 

 plants in which the leai'es or bracts are opposite {fig. 417) it 



Fig. 417. 



arises by the regular non- develop 

 ment of the axes on one side, 

 while those on the other side are 

 as regularly produced. This will 

 be readily explained by a reference 

 to the diagram {fig. 417). Here a, 

 represents the flower which ter- 

 minates the primary axis : at its 

 base are two bracts, only one of 

 which developes a secondary axis 

 b, which is in like manner ter- 

 minated by a flower, at the base 

 of which are also two bracts, only 

 one of which, (1. e. that on the same 

 side with the first,) produces a ter- 

 tiary axis c, also terminated by 

 a flower with two bracts at its 

 base, one of which gives origin to 

 another axis d, placed in a similar 

 manner, and so on. The place of the axis which 

 p2 



Fig. 417. Diagram to illustrate the 

 formatiou of a sciorpioid cyme in a 

 plant with opposite bracts or 

 leaves, a. Flower terminating the 

 primary axis. 6. Secondary axis. c. 

 Tertiary axis. d. Quaternary axis. 

 Each terminated by a flower. 



is unde- 



