164 



RESEARCHES ON FUNGI 



r 



n 



a 



A 



X 



the growing point of the hypha and thus 

 becomes decidedly concavo-convex (E,F). 

 After a few minutes it flattens again (G, H). 

 A second bulging forward followed by a 

 second flattening may also take place 

 (I, J) ; and even a third repetition of this 

 process has been observed. Finally, the 

 septum remains plane. Sometimes one 

 may observe that in a single hypha behind 

 the growing point the last 2-5 septa are 

 bulged forward toward the growing point 

 (Fig. 83), and that these septa, one by 

 one, in succession, beginning with the 

 oldest, become plane again. In the older 

 parts of a mycelium the septa are all 

 plane (Fig. 83). 



Careful observation with the high 

 power of the microscope revealed that 

 whilst a terminal septum is changing its 

 shape in the manner shown in Fig. 82 : 



Fig. 83. — Rhizoctonia solani ( = Corticium solani). 

 Temporary bulging forward of a series of 

 younger septa in a main hypha, as a result of 

 protoplasm being pressed toward the apical 

 growing-point : x, the basal part, and y, the 

 apical growing-point of a main hypha of which 

 the piece shown is 1-84 mm. in length. The 

 hypha was growing rapidly in a hanging drop 

 of nutrient gelatine. The four youngest septa, 

 nos. 5-8, are considerably bulged forward ; 

 the next youngest septum, no. 4, is slightly 

 bulged forward ; whilst the oldest septa, 

 nos. 1-3, are all plane. When the hypha was 

 first observed, its apex was at a and the septum 

 no. 3 was distinctly bulged forward. After an 

 interval of one hour, the apex had grown to y 

 and the septum no. 3 had become plane. In 

 general, both in the main hypha and in its 

 side-branches the older septa are all plane and 

 the younger ones are all curved forward. Each 

 septum has a small central open pore, and 

 protoplasm was seen moving slowly forward 

 through each of the eight septa of the main 

 hypha as indicated by the arrows. Drawn by 

 A. H. R. Buller and C. C. Neufeld. Magnifica- 

 tion, lti7. 



