1914] BRANNON—FASCIATION 525 



genital and sometimes post-genital, he has recourse to a theory of 

 Church, who holds that "growth is distributed at the apex of a 

 shoot in such a manner that its transverse component may be 

 expressed by a plane, circular construction around a circular point 

 (the growth center), and the circular section of the vast majority of 

 plant axes is evidently the outcome of such a regular and symmet- 

 rical distribution from the growing point/' Worsdell approves 

 of Church's theory that central distribution is distributed around 

 several points instead of about one center of growth. He holds 

 that some growth centers are weaker than others, hence develop 

 less in diameter and elongate more slowly, and this produces 

 torsion, which is an almost invariable component of fasciation. 

 Having developed this theory of centers of growth in different 

 radii of the apical region of a stem, he holds that any force 

 which upsets the. equilibrium of the organism will tend to bring 

 about a reversal to ancestral conditions. In other words, cylindri- 

 cal woods like those of our cottonwood and ash, upon losing then- 

 balance, will repeat the long-past experience of lycopods, ferns, and 

 algae, where branching primarily is probably in one plane. 



Worsdell furthermore treats of plant monstrosities as a 

 possible pathological condition. He refers to it as a subtle dis- 

 eased condition brought about by superabundant nutrition that 

 destroys the balance of the organism and produces hypertrophy of 

 parts. It is pointed out that the crested form of Celosia argentea 

 is not produced abundantly without manuring the potted plants. 

 Wors dell's conclusion is that there are morphogenetic principles 

 underlying the phenomenon of fasciation. He holds that fasciation 

 is to be explained as a resultant of the more or less equal conflict 

 waged between two opposing tendencies or forces, one of which 

 induces integrity of parts of a plant and the other induces 

 plurality of parts. 



In a recent discussion, White 4 reviews interesting genetic 

 studies based upon a fasciated variety of Nicotiana Tabacum. The 

 race of these fasciated specimens was obtained from the self-fed 

 seed of a mutant found growing in a field of Cuban tobacco. He 



4 White, O. E., The bearing of teratological development in Nicotiana on theories 

 of heredity. Amer. Nat. 47:216-228. 1913. 



