392 
Journal of Agricultural Research 
Vol. XXVII, No. 6 
and P. graminis than any other wheat grown at University Farm, St. 
Paul. The collenchyma areas are extremely small and mak e up but 
little of the stem structure. The sclerenchyma areas are decidedly pre¬ 
dominant in this variety and make up the major portion of the stem 
proper. The unevenness of the surface made by the bulging out of the 
Fig. i.—T racings of transverse sections of the upper peduncle or neck of different wheat varieties. The 
sclerenchymatous tissues are represented by the black areas. Note the practically continuous band of 
collenchyma just under the epidermis in B; note also the relatively large collenchyma bundles in D. 
A. — Sonem emmer, C. I. 4402. 
B. —Tittle Club, C. I. 4066. 
C. — Vernal (White Spring) emmer, C. I. 3686., 
D. —Marquis, C. I. 3641. 
E. —Kota, C. I. 5878. 
F. —Einkom, C. I. 2433. 
sclerenchyma between the chlorophyll-bearing areas is very prominent. 
This condition is characteristic of all the emmer varieties studied, although 
the unevenness is particularly evident on Sonem emmer. 
Figure i, B, shows a tracing of a section of Little Club, C. I. 4066. 
This variety as infected by rust in the field, is shown in Plate 1, E. 
