534 MR, A. LISTER ON THE DIVISION OF 



Comatricha of 7.35. The stage showing the nuclear spindles, 

 matching with the 7.15 staining of Comatricha, was missed in 

 this series; but one of a less carefully timed preparation of 

 another gathering of Physarum leucophceiim supplied the gap. 

 The small nuclear bodies (mostly contained in a vacuole) were 

 numerous in this slide. 



10.25. Young spores formed containing a small discoid nucleus, 

 corresponding with the 8 p.m. staining of Comatricha. 



10.40. Nuclei in the young spores spherical. 



On Dec. 5 a piece of rotten wood bearing a crop of young 

 Trichia fallax was placed under a bell-jar, and stainings were 

 taken which showed karyokinesis about an hour before spore- 

 formation ; but it was not a healthy development, probably owing 

 to their having been exposed to frost when the plasmodium w r as 

 just emerging* However, on Dec. 12 a growth of upwards of 200 

 sporangia came up in rosy globules on the same piece of rotten 

 wood, which had remained all the time under the bell-jar. 

 This gave an opportunity for preparations being made under the 

 most favourable conditions with no danger of the disturbance to 

 which plasmodium is liable when removed from its natural 

 surroundings. In addition to the interest attaching to Trichia 

 fallax as having been examined by Strasburger, it is a species 

 representing a group which are slower in maturing than Coma- 

 tricha or Physarum ; for whereas in the latter genera the spores 

 begin to form within 12 hours from the time when the sporangia 

 first make their appearance, in Trichia this process takes nearly 

 four times as long and the spores are not fully ripe under about 

 four days. 



The following record gives the times when the sporangia were 

 examined. It will be noticed that those taken at 10.20 and 

 10.40 on Dec. 13 do not follow in regular sequence, which is 

 probably due to the fact that in this species the sporangia do 

 not rise from the matrix quite simultaneously, so that some are 

 rather more backward than others. 



Dec. 12, 10 a.m. 



fi 



globes. Nuclei showing a reticulated structure and containing 

 one or two nucleoli. 



4 p.m. Sporangia ovate, stalked ; nuclei as at 10 a.m. 



9 p.m. No elaters formed, but vacuolar cavities showing in the 

 protoplasm. 



Dec. 13, 8.30 a.m. Elaters formed with rounded ends, no 

 spiral markings ; nuclei unaltered 



