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 diiferent 

 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 divides into two new growing points, from which branches 

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

 f i 



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

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

 also the di<^b(isium) • D, helicoid cyme. — ^Af ter 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 dichotomy, in whicli both branches of each bifurcation are 

 equally developed (Fig. 118, A). 



* Acropt-tal, tending toward tlie summit ; frim the Greek aupa, 

 summit, and -ireTau. to move toward. 



