THE TRANSLOCATION OF PROTOPLASM 



163 



in Rhizoctonia solani (Fig. 82, A-D), about 10 minutes ; and in the 

 Ciboria that grows on male Birch catkins, about 6 minutes. 



Temporary Bulging of Septa toward Growing Points. 1 — A 



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51 



Fig. 82. — Rhizoctonia solani (= Corticium solani). Successive stages in the 

 formation and temporary bulging forward of a septum, represented in 

 optical median-longitudinal sections. A, the middle part of the terminal 

 cell of a rapidly-growing hypha in which a new septum is about to be formed 

 at the level a ; the protoplasm, as indicated by the arrows, is very slowly 

 flowing toward the apical growing-point of the main hypha and toward 

 the apical growing-point of the main hypha's lateral branch. A was drawn 

 at the zero of the time-scale, and the time in minutes at which each of the 

 other stages was drawn after A is indicated above each of the drawings 

 B-J. The total time in which all the changes were observed was 

 52 minutes. B, the septum, in the form of an annular ingrowth from 

 the lateral wall, has begun to form. C, the septum is more than half -formed. 

 D, the septum is complete : it has taken about ten minutes to form and has 

 an open pore left at its centre ; through the pore protoplasm is slowly 

 passing from the subterminal cell to the growing-point of the terminal 

 cell. E, the septum is becoming bulged in the direction of the flow of 

 protoplasm. F, the septum is now bulged forward to the maximum 

 extent. G, the septum is flattening again. H, the septum is now plane. 

 I, the septum has become bulged a second time. J, the septum has become 

 plane again. Drawn by A. H. R. Buller and C. C. Neufeld. Magnification, 

 1007. 



septum of Rhizoctonia solani, whilst being formed, is plane (Fig. 82, 

 D) ; but, very soon after its formation, it bends forward toward 



1 This phenomenon was first observed and then brought to my attention by my 

 research assistant, C. C. Neufeld. 



