52 



RESEARCHES ON FUNGI 



to the tropic stimulus when about 12 y. apart. In B the two hyphae 

 have completely fused. The time which elapsed between stage A 

 and stage B was 10 minutes. 



Stages in two hypha-to-peg fusions are shown in Fig. 26. In A 

 the hypha a has induced in the hypha b the formation of the peg c 

 and the ends of both hypha and peg are growing toward one another. 



Fig. 26. — Pleurage curvicolla. Stages in the formation of two hypha-to-peg fusions. 

 A : the hypha a by chance approached the hypha b obliquely ; when about 

 15 yu away from b, it turned toward b and caused b to send out the peg c ; the 

 ends of the hypha a and the peg c are now growing toward one another. Similarly, 

 the hypha d grew toward the hypha e and caused e to send out the peg / ; the 

 ends of the hypha d and of the peg / are now growing toward one another. B, 

 10 minutes after A : the hypha a and the peg c are now touching at their ends ; 

 the end of the hypha d is almost touching the end of the peg /. C, 5 minutes 

 after B : both of the hypha-to-peg fusions are now complete. Magnification, 

 434. 



In B, 10 minutes after A, the hypha and peg have just met ; while 

 in C, 5 minutes after B, the hypha and peg have fused. In A the 

 hypha d is curved toward the peg / which has grown out from the 

 hypha e. In B, 10 minutes later than A, the hypha and peg are 

 turned toward one another and have almost touched. In C, 5 

 minutes after B, the hypha d and the peg / have fused with one 

 another. 



The later stages in the hypha-to-peg fusion d-x at the top of 

 Fig. 24 were observed. The end of the hypha d grew toward the 

 side of a thin branch-hypha of the mycelium c and ; apparently, so 



