THE FORMATION OF HYPHAL FUSIONS 51 



hypha-to-peg, and peg-to-peg fusions were all observed coming 

 into existence. 



Two stages in a hypha-to-hypha fusion, drawn with the camera 



Fig. 25. — Pleurage curvicolla. The formation of a hypha-to-hypha 

 fusion. Spores, of which one is shown, were sown in cleared 

 dung-agar about 20 hours before the drawing A was made. In 

 A are seen two branch-hyphae, a and b, which at first grew 

 independently of one another in the culture medium, but by 

 chance came near to one another. When about 12 /u apart, 

 they stimulated one another, with the result that their ends 

 are now growing toward one another. Half an hour later their 

 ends had met and fused, as shown in B. In A, c is probably a 

 hypha-to-peg fusion, while d, e and / are all peg-to-peg fusions. 

 Magnification, 434. 



lucida, are shown in Fig. 25. In A the two branch-hyphae a and 6 

 which at first were growing independently of one another in the 

 culture medium have now become stimulated by one another and 

 their ends are growing toward one another. They began to react 



