232 



RESEARCHES ON FUNGI 



convincing evidence of the value of the three-dimensional netting 

 of a haploid mycelium in- so far as the process of diploidisation is 

 concerned. Had the radial hyphae in the hollow mycehal ring not 

 been all linked up together by numerous bridges formed by their 



lateral hyphae, the 

 nuclei derived from 

 the inoculum could not 

 possibly have travelled 

 tangentially around the 

 (o/Lv mycehal ring and have 

 / brought about the dip- 

 loidisation of all the 

 tens of thousands of 

 peripheral hyphae on 

 the ring's outer side. 



Experiment No. 3. 

 A haploid mycehum 

 (AB) was grown in a 

 large Petri dish on 

 dung-agar until it had 

 attained a diameter of 

 6-5 cm. Then there 

 were cut away from it 

 on two opposite sides 

 (together with the agar 

 below) two large and 

 equal outer pieces {g 

 and h in Fig. 132) so 

 as to leave behind 

 the dish a band 



Fig. 131. — Coprinus lagopus. The diploidisation of 

 a large haploid mycelium having the form of a 

 hollow ring by means of a small haploid mycelium 

 of opposite sex deposited at its outer pe^ipherJ^ 

 A haploid mycelium (AB) was allowed to grow 

 on dung-agar in a large Petri dish until it had 

 attained a diameter of 6 • 1 cm. Then there was 

 removed from it (together with the agar below) 

 a central portion 3 • 8 cm. in diameter. The ring 

 of mycelium left behind in the Petri dish was 

 then inoculated at one spot on its outer periphery 

 with a tiny fragment of a haploid mycelium (ab), 

 as shown in the illustration. Within six days 

 the haploid inoculum [ah) had completely 

 diploidised the large haploid myceliimi [AB). 

 The arrows inside the {AB) mycelium on eacli 

 side of the inoculum indicate the directions in 

 which the (AB) mycelium became progressively 

 diploidised as indicated by the successive ap- 

 pearance of clamp-connexions on all the leading 

 peripheral hyphae 



in 

 of 



Natural size 



mycelium 6-5 cm. long 

 and 2-0 cm. wide, the centre of the band being the original centre 

 of the mycehum. Then the band of mycelium {AB) was inoculated 

 at one end with a tiny fragment of a haploid mycelium {ab). 



Nine days after inoculation, clamp-connexions began to appear 

 at the end of the mycelial band opposite to that to which the inoculum 

 had been applied and 9-5 cm. distant therefrom (Fig. 132). 



