thicker, and the same is true of the portion above. Splitting the 

 ovary lengthwise the same change is found to have taken place in 

 the ovule, or rudimentary seed, which has grown up on a long stalk 

 (see figs. 12 and 13). A further peculiarity is shown in fig. 14. 

 This is the sharp turn upward which the affected pistils take, just as 

 the stem of a plant takes when bent over. Further changes are 

 found in the pappus, the circle of capillary hairs at the top of the 

 ovary. These normally consist of fine stiff bristles, having the struc- 

 ture shown in fig. 15, a. In diseased florets the pappus is mostly 

 undeveloped and its place taken by a fringe of small lobes, having a 

 cellular structure and containing chlorophyll, forming something of 

 a true calyx, which the pappus represents (fig. 15, b.). 



The changes in the plant under the influence of this disease 

 may be summarized something as follows :. 



Root: Apparently well developed and entirely normal, even 

 in worst cases. 



Stem and Branches : No structural change. Pale yellow color, 

 poor in chlorophyll, often slender and spindling. In worst cases 

 stunted and very short. 



Leaf : No structural change. Color yellowish and sickly. Poor 

 in chlorophyll. Often poorly developed in size and form. 



Flower : Bracts, no change. 



Calyx (Pappusj, apparent tendency to revert to leaf-like lobes or 

 sepals. All stages of transition occur between the proper branching 

 hairs and chlorophyll-containing lobes or bract-like scales. 



Corolla, color — changed to uniform light greenish-yellow without 

 regard to original shade. Form — in ligulate ray florets slender and 

 closely incurved, appearing tubular. In disc florets elongated, retain- 

 ing tubular form with short lobes at extremity. 



Stamens, general tendency to abort. Anthers small and shrivelled, 

 producing little or no pollen, not cohering in a ring about the pistil. 



Pistil — general tendency to elongate. Stig?)ia much elongated and 

 enlarged, protruding abnormally from the corolla tube. Ovarj much 

 elongated and somewhat enlarged. Few hairs on outside. Ovule 

 elongated, shrivelled and apparently not fertilized. Funiculus espe- 

 cially grows very long, keeping pace with the ovary. 



