Studies of Teratological Phenomena. 51 



The character of my material has made possible a tabular pre- 

 sentation of data which will give one an unprejudiced picture of the 

 actual results from a study of the inheritance of fasciation. The 

 meristic nature of this character makes such results a I have obtained 

 more nearly free from the personal element than those involving studies 

 such characters as colors. Further studies of this particular character 

 are in progress^). 



The major portion of this investigation was carried on- under the 

 direction of Prof. E. M. East, to whom much credit is due, for helpful 

 criticism and encouragement. I wish also to express my appreciation 

 for the helpful suggestions and criticisms given me by other members 

 of the biological faculty of Harvard, and to Director J. H. Maiden, of 

 of the Sydney Botanic Gardens for the compilation of data on the 

 occurrence of fasciation in Australia. I have drawn on the papers of 

 several investigators for text illustrations and for these I have given 

 proper credit in connection with the legends. 



B. Definition, occnrrence and distribution. 



Fasciation, as commonly defined, is a flattened, strapped-shaped or 

 ribbon-like expansion of the main axis or axillary organs of a plant; at 

 the base it is generally cylindrical, at the apex, combed (truncate), or 

 diffusely branched in "witch-broom" fashion. Its presence in a plant 

 may alter the arrangement of both foliar and floral leaves, and increase 

 their number. Under classification, detailed information concerning both 

 morphological and physiological aspects of this anomaly are given, 



Taxonomically, fasciation is a very widely distributed anomaly, 

 largely confined it would seem to the vascular plants, as I have been 

 unable to find records of tji^ical cases occurring in the lower groups. 

 Hus (1908, p. 83) cites its presence in fungi, but gives no descriptions 

 or references to where such data may be found. More or less typical 

 fasciations have been recorded from 102 of the 290 families into which 

 En gl er (1909) divides the living vascular plants. These 102 families 

 are listed in alphabetical order in Table A. According to this table, 

 less than two fifths of the total number of families have contained 



^) The greater part of this study was presented in 1913, in partial fulfillment 

 of the thesis requirement for the degree of doctor of science of the Bussey Institution 

 of Harvard University. 



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