GENERALIZED FORMS. 



139 



(4.) They always arise in acropetal* order. 



(5.) They grow more rapidly than the caulome does above 

 their insertion. When they are numerous their rapid growth 

 gives rise to the accumulation of phyllomes known as a Bud. 



(6.) The phyllomes of any plant are always of a different 

 form than the caulomes. 



177. General Modes of Branching of Members. There 

 are two general modes of the branching of the members of 

 the plant-body. In the one, the apex of the growing mem- 

 ber diA r ides into two new growing points, from which branches 

 proceed ; this is the Dichotomous mode of branching (Fig. 



m 



/ 



a , 



? 



Z 



/ 









6 J 



Pig. 120. Diagrams of cymose monopodial branching. A and B, scorpiold cymes ; 

 67, forked cymose monopodium, the compound or falsely dichotomous cyme (called 

 also the dichasium) 2), helicoid cyme. After Sachs. 



118). In the other, the new growing points arise as lateral 

 members, while the original apex of the parent stem still 

 retains its place and often its growth ; this is the Mono- 

 podial mode of branching (Fig. 119). Both modes are sub- 

 ject to many modifications, the most important of which are 

 briefly indicated in the following table : 



A. DICHOTOMOUS. 



1. Forked dicJwtomy, in which both branches of each bifurcation are 

 equally developed (Fig. 118, A). 



* Acropetal, tending toward the summit ; from the Greek dxpa. 

 summit, and Trcraw, to move toward. 



