RATE OF MOVEMENT OF NUCLEI 219 



(2) Maximum rafe of movement of nuclei. An attempt was made 

 to determine the maximum speed with which nuclei can pass 



Fig. 126. — Coprinus lagopus. The diploidisation of a large liaploid mycelium {AB) 

 by a small diploid mycelium {AB) + {ab). The large haploid mycelium was 

 allowed to grow on cleared dung-agar imtil it wns 6-2 cm. in diameter. It 

 was then inoculated at its periphery with a tiny hyphal mass of (AB) + {ab) 

 mycelium which can be observed on the right-liand side of the photograph 

 1-5 cm. from the peripliery. At the end of 74 hours after inoculation, the 

 large haploid myceliiun had become completely diploidised by the diploid 

 mycelium, as shown by the appearance of clamp-connexions on all its peripheral 

 leading radial hyphae {vide Fig. 118). The photograph was taken five days 

 after inoculation and two days after the large haploid myceliiun had become 

 completely diploidised. The darkness of the central part of the myceliuiu is 

 due to tlie aerial hyphae having become submerged in liquid excreted by oidio- 

 phores when the mycelium was in the haploid state. The hyphae which com- 

 pose the outer fluffy white ring are diploid and bear no oidiophores. Natural size. 



through a haploid mycehum which is being diploidised. Therefore, 

 in the eight experiments just described, the plates were examined 



