248 



PRINCIPLES OF PLANT-TERATOLOGY. 



become 2-merous, is placed medianly, instead of, as 

 Heinricher (and also Eichler) found in other com- 

 pletely 2-merous flowers (fig. 150 c), alternating with 

 the two-keeled posterier bracteole and the bract, i. e. 

 being transversely placed. The two variations of the 



2- merous flowers may be explained as follows : When 

 the two perianth-leaves of the first whorl arise in the 

 transverse position, they clearly constitute a 2-merous 

 simultaneous whorl, alternating with bract and brac- 

 teole. In the 3-merous outer whorl, however, the 

 leaves arise as usual successively, the two first ones, 

 according to Payer and Schumann, behind, and in 

 front of the two-keelecl bracteole (which arises with 

 two lateral rudiments), the third one much later and 

 anterior. When this whorl becomes 2-merous, retaining, 

 however, the successive mode of origin, so that the 

 distichous arrangement is brought about, then the first 

 perianth-leaf is posterior and the second opposite to it 

 and anterior. Herewith we obtain transitions from the 

 original 3-mery to 2-mery in such a way that the first 

 leaf represents a double-leaf (leaves one and two of the 



3- merous whorl united)." 



The main reason why the posterior leaf is in front 

 of the bracteole must be sought in the fact that in 

 reality this latter represents two leaves which have 

 recently fused. 



The excessively reduced flowers (1-merous in one 

 or two cases), observed by Magnus, Prillieux, and 

 Stenzel (placed in the following section) are naturally 

 followed by those in which all or most of the whorls 

 are entirely suppressed, and if any one is left it is quite 

 vestigial. Examples are afforded by the cauliflower 

 and broccoli, in which, owing to excessive hypertrophy 

 of the pedicels, the flowers are not developed, or only 

 a vestigial calyx. In the feather-hyacinth (Muscari 

 comosum), again, owing to the inordinate and copious 

 branching of the pedicellar system, the flowers are 

 almost entirely suppressed. The two cases mentioned 

 are sports or abnormalities. But normally precisely 



