460 Gregory : Effects of pressure on roots of Vicia Faba 



has had no effect on the mitotic figure or division wall in the 

 root cells of Vicia Faba. At first it was thought that the pres- 

 sure had caused an increased number of transverse and oblique 

 spindles. In one series a row of transverse spindles was found in 

 the periblem layer at a point near the meristematic region. The 

 control series, however, showed transverse spindles in an equally 



p 



4 



» 



Figure I, A median longitudinal 

 section through a root to which 858 

 grams of pressure had been applied. 

 Note the empty cells in which the 

 split will take place, also the de- 

 generating plerome cells on either 

 side. The periblem layer is only 

 slightly affected by the pressure. X 

 530. 



Y 



X 



Figure 2. Alowpower sketchof 

 the condition found in a root 10 



which 1560 gi-ams of pressure had 

 been applied. The dark area rep- 

 resents the periblem tissue in which 

 rifts have occurred. ^:z= periblem 



cells which have been displaced. 

 Y= plerome cells which also have 

 been displaced. 



anterior region, and also as many oblique spindles as had been 

 found in the compressed roots. In no way did the mitotic figure 



