Studies of Teratological Phenomena 



in their Relation to Evolution and the 



Problems of Heredity. 



II. The Nature, Causes, Distribution, and Inheritance of 



Fasciation with Special Reference to its Occurrence in 



Nicotiana^). 



By Orland E. White, 



Brooklyn Botanic Garden, Brooklyn, N. Y., U. S. A. 

 (Eingegangen 1. Juli 1914.) 



Contents. 



A. Introduction p. 50 



B. Definition, occurrence, and distribution „ 51 



C. Classification „ 56 



1. Morphological „ 57 



a) Morphological theories „ 62 



2. Physiological „ 63 



a) General considerations „ 63 



bj Inherited (germinal) form of fasciation „ 68 



c) Uninherited (somatic) form of fasciation „ 70 



D. Discussion and summary of Parts B and C „ 75 



E. Review of Mendelian studies „ 78 



1. Pisum „ 78 



2. Zea mays „ 79 



F. SpecialstudyoffasciationinNicotiana „ 82 



1. Problems „ 82 



2. Materials and methods „ 82 



a) Description of species and varieties used in the investigation . . . „ 83 



b) Number of plants grown „ 94 



c) Methods „ 94 



^) Contribution from the Laboratory of Genetics, Bussey Institution of Harvard 

 University. Brooklyn Botanic Garden Contributions, No. 11. 



Induktive Abstammungs- uud Vererbungslehre. XVI. 4 



