RATE OF MOVEMENT OF NUCLEI 221 



In all the eight experiments the inocula for the central haploid 

 mycelium and for the excentric haploid or diploid mycelium were 

 tiny masses of surface hyphae (no agar) about the size of a pin's 

 head ; and these inocula in Figs. 124, 128, and 129 are represented 

 by black dots. The limit of growth of each mycelium was marked 

 each day in blue pencil on the under side of the plate and thus 

 a series of concentric circles was obtained. The beginning of a typical 

 experiment, i.e. when the second inoculum had just been added to 

 the plate at the periphery of the large central haploid mycelium, 

 is represented in Fig. 124 (p. 215) ; while the end of two experi- 

 ments, No. 1 and No. 2, is represented in Figs. 128 and 129 

 respectively. 



The greatest speed of nuclear movement (hmits of movement 

 shown by the production of clamp-connexions) was found for experi- 

 ments No. 1 and No. 2 in Table II ; and the data in respect to these 

 experiments will be elucidated with the help of Figs. 128 and 129 

 respectively. 



In both the experiments No. 1 and No. 2 the central haploid 

 myceUum was inoculated at its periphery when nine days old 

 (c/. Fig. 124), and the external limit of the central mycelium at that 

 time is indicated for Experiment No. 1 in Fig. 128 and for Experi- 

 ment No. 2 in Fig. 129 diagrammatically by means of an inner 

 heavier circle (No. 9). The outer heavier circle in Figs. 128 and 

 129 shows the limit of mycehal growth on the day on which the 

 diploidisation of the large central haploid mycelium had become 

 complete. 



(3) Experiment No. 1 .• a haploid mycelium inoculated with a hap- 

 loid mycelium. In Experiment No. 1, a large haploid mycelium 

 {AB) was inoculated with another haploid mycelium (ab) when, as 

 shown in Fig. 128, it was 6-0 cm. in diameter. The time at which 

 the {ab) inoculum was added to the plate will be taken as the zero 

 hour for the experiment. 



It doubtless took several hours for the two haploid mycelia to 

 meet and fuse ; but, by the end of 42 hours after the (ab) inoculum 

 had been added to the plate, clamp-connexions were observed at 

 the periphery of the {AB) mycelium proceeding away from the 

 {ab) inoculum to a distance of 6-0 cm. on one side and 5-3 cm. on 



