234 



RESEARCHES ON FUNGI 



From the observations just recorded for Experiment No. 3 we 

 may conclude that the nuclei derived from a small peripheral 

 inoculum, when advancing through a large haploid mycelium which 

 is becoming diploidised, can travel through the middle and oldest 

 part of the mycelium. 



The large haploid mycelium used for Experiment No. 3, like all 

 the other large haploid mycelia used for other experiments, had 

 produced a great number of oidiophores and a still greater number 

 of oidia at its surface everywhere except at its extreme edge where 

 its peripheral hyphae were elongating radially. It is therefore clear 

 that nuclei derived from a small peripheral inoculum, when advanc- 

 ing through a haploid mycelium which is becoming diploidised, can 

 move through regions of the mycelium in which oidial production 

 has been very active. 



It is certain that, when a large haploid mycelium is becoming 

 diploidised by nuclei derived from a small inoculum, all the actively- 

 growing peripheral hyphae of the mycelium become diploidised, but 

 it may well be that many of the hyphae in the more central and 

 older parts of the mycelium — which have been engaged in the 

 production of oidia, have ceased to grow, and are not likely to form 

 fruit-bodies — may never become diploidised but may remain in the 

 haploid condition until they become exhausted through their 

 contents being drawn to fruit-bodies developing on diploid portions 

 of the mycelium. 



Conclusio7i from Experiments Nos. 1, 2, and 3. The results 

 obtained from the three experiments described above indicate that 

 the nuclei derived from a tiny mycelial inoculum, when advancing 

 through a large haploid mycelium which they are diploidising, may 

 travel through any part of the mycelium, old or young, but that 

 they move more readily through a younger part than through an 

 older part. 



A Sex-factor Analysis of a Diploid Mycelium derived from a 

 Larg-e Haploid Mycelium which has been diploidised by a Small 

 Diploid Inoculum. — Experiment No. 1. A haploid mycelium {Ab), 

 which was No. 1 in Table I (p. 214), was grown on dung- agar in a 

 large Petri dish until it had attained a diameter of 5 • 2 cm. It was 

 then inoculated at one place on its periphery with a tiny fragment 



