THE FORMATION OF HYPHAL FUSIONS 



53 



stimulated this branch-hypha that the latter sent out two opposing 



pegs. Both of these 



pegs grew toward the 



end of the hypha d ; 



but, eventually, as was 



actually observed, the 



peg x alone fused with 



the hypha d and then 



the other peg ceased to 



grow. 



Several peg-to-peg 

 fusions were observed 

 being formed. Among 

 them two are illustrated 

 in Fig. 27. In A, the 

 two pegs a and b have 

 originated opposite to 

 one another on two older 

 more or less parallel 

 hyphae and they are al- 

 ready bending their ends 

 toward one another. 



In B, a few minutes 



later than A, the two 

 pegs are shown after 

 their fusion. The dis- 

 tance apart of the two 

 older hyphae where the 

 pegs were produced was 

 about 15 [x. 



In Fig. 27 there 

 are also illustrated two 

 stages in the formation 

 of a fusion associated 

 with three pegs. In A, 

 the peg c produced on 

 the older hypha q is faced 



Fig. 27. — Pleurage curvicolla. The formation of 

 two peg-to-peg fusions. (1) As shown in A, 

 the two more or less parallel hyphae, o and p, 

 have sent out opposing pegs, a and b, the ends 

 of which are growing toward one another. 

 Within a few minutes these pegs met and fused, 

 and thus formed a bridging hypha, as shown in 

 B. (2) As shown in A, the hypha q sent out a 

 single peg c and the hypha r two opposing pegs, 

 d and e. All three pegs at first grew straight 

 forward. Then the pair of pegs d and e grew 

 toward the single peg c, but the latter turned 

 toward e alone and eventually fused with it, 

 as shown in B. After the fusion had taken 

 place, the peg d ceased to grow. A narrow 

 bridging hypha / joining the hyphae o and r 

 had been formed, presumably from two pegs, 

 before the drawling A was made. A scale in 

 micromillimeters is given in A. Magnification,847. 



right and left by two pegs d and e produced 



