THE STEM OR SHOOT. 



85 



Mikle observed abnormal forking in the rhizome of 

 Botrychium. 



Schoute observed true dichotomy of the stem, as a 

 normal feature, in Hyphsene, an African palm. This 

 is the first discovery of the kind in Phanerogams. It 

 arose as follows : '* The apical meristem ceased to 

 grow, and in place of it, at equal lateral distances 

 therefrom, two new ones appeared." From this it is 

 obvious that there was no division of the apical meri- 

 stem into two, and yet true dichotomy is present : 

 because the two lateral branches did not arise owing 

 to injury to the stem-apex ; because they are not 

 axillary to any leaves; and because an " angle-leaf " 

 is present opposite the fork precisely as is the case in 

 dichotomizing stems of Cryptogams. Moreover, the 

 two branches bore lateral buds in the axils of every 

 leaf. Velenovsky has also established by personal 

 observation that true dichotomy occurs in Ghamsedorea 

 Martiana. 



Fasciation or multiple dichotomy is such a wide- 

 spread phenomenon, occurring in all groups of 

 vascular plants, that particular instances need hardly 

 be specified, but the case may be briefly mentioned of 

 a plant of the feather asparagus (A. plumosus) whose 

 main shoot was fasciatecl, some of the minor branches 

 being affected in the same way, becoming " crested," 

 thus still further adding to the normal fern-like aspect 

 of the plant (PI. VI, fig. 2). 



There may also be cited the case of the potato var. 

 Hoornkens, figured in the 6 Tribune Horticole,' whose 

 tuber was palmately branched. 



In those cases of fasciation in which no apical 

 splitting occurs it might be thought that no comparison 

 could be instituted between such a fasciation and the 

 dichotomous shoot ; but a little investigation and 

 reflection will reveal that in reality a fasciated or 

 ribbon-shoot consists ipso facto of a number of inde- 

 pendent growing points embedded in a common 

 matrix, i. e. still linked together in linear fashion 



