ORGANS OF EEPRODtrCTION. 



201 



distinguished from indefinite kinds of inflorescence, such as the 

 iinibei, or corymb, to which otherwise they bear in many cases 

 a great resemblance. In the Chickweed {fig. 408), and many 



Fig. 410. 



Fig. 410. Spiked cyme of 

 Sediim. Fig. 411. Race- 

 mose ciiue of a Campa- 

 nula, a'. Primary axis, 

 terminated hy a flower 

 /', which Is already withering, 

 ing iu a flower,/",/",/". 



", a", a". Secondary axes, each end- 



other plants, the formation of the secondary and other axes a" 

 a'" a"" goes on throughout the gi'ovving season, and in such cymes, 

 which are usually of a more or less spreading nature, the centri- 

 fugal or ci/mose (as it is also called) order of expansion may 

 be well observed. 



The above cymes are characterised as dickotomovs, or tri- 

 choto-mous, according to the number of their branches ; thus 

 they are dichotomous, as in the common Centaury {Eri/thraa 

 Ccntaurium) {fig. 409), when the primary axis a' is terminated 

 by a flower/', at the base of which are two bracts, each of which 

 developes in its axil secondary axes a" a", ending in single 

 flowers,/"/"; and at the base of each of these flowers there are 

 also two other bracts, from which tertiary axes a"' are developed, 

 also terminated by flowers/"', and so on, and as the division in 

 this case always takes place into two branches, the cyme is said 

 to be dichotomous. The cyme of the Chickweed {fig. 408) is also 

 dichotomoics. If the division of the cyme takes place in threes, 



