INDUCTION, DEVELOPMENT, AND HERITABILITY OF !• ASCIATIONS. 



Study of fasciation is naturally i^-nniped about these two i^eriods. The 

 character of the fasciated rosette, with broad, linear heart, .ii^ivino- rise to 

 stems flattened from the base, has been made familiar by de Vries (11). In 

 the cultures such rosettes reached a breadth of 3 cm., and the stalk from 

 one of them produced a veg'ctative line which eventually measured 38 cm. 

 (plate i). In other cases the first evidence of fasciation in the rosette is a 

 bifurcation of the .qrowins' region, and two tiny buds sometimes appear even 

 between the cotjdedons. The two types of rosettes are illustrated by plate ii, 

 fiS'. 4, and by text-fig-. 1. The fasciation of the flowering- stalks is far more 



common than that of the rosette and 

 furnishes the bulk of the material for 

 observation, as well as for histological 

 examination. Usually the rosettes 

 have been plants to be kept for other 

 experimental purposes, but the late 

 branches may be cut at will. The 



Fig. I. — Raiinannia odorata, bifurcated 

 rosette. 



flowering stems studied came mostly 

 from two sets of plants — the wild 

 O. bioinis and the O. critciata in the 

 garden. There were man\- ring- 

 fasciations in the two groups, though 

 these have been comparatively infre- 

 quently rei^orted. The O. biennis, 

 besides simple fasciations and ring- 

 fasciations, showed on many stems, 

 associated with the banding, an indentation or groove, as represented in 

 plate II, fig. 2, running up the upper half of the stem. The groove became 

 wider and deeper as the stem flattened . Simple fasciations , ring-f asciati(ms . 

 and groove-fasciations occurred together, both on secondary and tertiary 

 branches of plants of which the main axis had usually been stunted. Two 

 descriptions may be taken as representative: 



Plant 1.- The plant had ii branches, which were all equal in importance, the main 

 tip having been stunted early in its history. There was consequently no main branch, 

 though A was the largest secondary branch. The tip of A was also stunted, and it had 

 1 1 tertiary branches; of these, 7 were fasciated. The fasciations were split into two or more 

 forks. Two of them showed round instead of flat divisions. In six cases below the 

 bifurcations there were grooves. The secondary branch B was also fasciated, with a flat 

 tip. The flattening was in every case associated with old capsules, often with holes 

 bored through. 



Plant 2.— The plant had 9 branches. The branch A had 6 secondary branches, all 

 of which were fasciated. Two of them showed ring-fasciations, the others were flat, and 

 two exhibited conspicuous grooves. Of the other branches, one showed a ring-fasciation 

 and the others bifurcations and simple fasciations; 5 of them showed grooves so as to 



be recognizable. All of the main branches were fasciated. 

 ciations on the plant was 15, 



The total number of fas- 



