122 COMPOUND OBGANS OF PLANTS. 



indeterminate manner, but are arrested in their development 

 by the terminal flowers. 



The most common and regular cases of determinate inflo- 

 rescence occur in opposite-leaved plants. In these plants the 

 inflorescence is composed of a superposed series of bifurcations 

 of the primary axis, in the centre of each of which a terminal 

 flower is situated. This mode of inflorescence, which is termed 

 a cyme, has been already explained, and may be studied to 

 advantage in the chickweeds, (Cerastium and Stellaria,) in 

 which it is recognizable at once by the solitary flower, destitute 

 of bracteoles, in each fork of the branches. 



Fig. 28. Fig, 29. 



Sometimes only one of the two bracts on the primary and 

 succeeding axes developes a flower, as in Arenaria striata, (Pig. 

 28 ;) or the floral bract is suppressed altogether, so that the 

 flower appears opposite the remaining bracts, (Fig. 29 ;) or 

 both bracts are suppressed, and the flowers only are developed, 

 as in Myosotis palustris, (Pig. 30.) When this is the case, 

 the cyme assumes a remarkable curvature, turning round in a 

 p3culiar way so as to resemble a snail or the tail of a scorpion, 

 and hence it is called a helicoid or scorpioid cyme; (tiiti, a 

 spiral, and itSoi, form.) This form of inflorescence may be 



