COPRINUS STERQUILINUS 217 



at 2 A.M., stage g at 2.30 a.m., stage y^ at 3 a.m., and stage i at about 

 8 A.M. Hence it is clear that the growth of the spores from their 

 first tiny rudiments on the top of the sterigmata to full size is a 

 long process which takes about nine hours for its accomplishment. 

 For several hours (at least three) after a spore has attained its full 

 size, it remains colourless, and then its inner wall slowlj^ becomes pig- 

 mented. Stage J which shows the spores turning brown was sketched 

 at 7 P.M., i.e. eleven hours after the stage i, and stage k which shows 

 the spores fully pigmented was sketched at 1 2 midnight . My observa- 

 tions indicate that a spore, after attaining full size, takes about 

 twelve hours before it becomes fully pigmented. The stage k per- 

 sisted from 12 midnight to about 6 A.M., at which time spore-discharge 

 began. At the stage I, which represents the condition of a basidium 

 at about 6 a.m., two spores have been discharged and a third is 

 about to be discharged. The spore about to be discharged is the 

 one which has just excreted a drop of fluid at its hilum ; for here, 

 as in all other Hymenomycetes,^ the appearance of the drop is a 

 signal that the moment of discharge is to be expected within a 

 very few seconds. At the stage m, representing a basidium at about 

 6.10 A.M., the last of the four spores has just been discharged, but 

 the basidium-body is still turgid. At the stage n, representing a 

 basidium at about 6.40 a.m., the basidium-body has collapsed and 

 is undergoing autodigestion ; and, finally, at the stage o, repre- 

 senting a basidium at about 7 a.m., the whole basidium has become 

 reduced to but a shadow of its former self and is rapidly becoming 

 disintegrated. 



The various observations which have been made upon the de- 

 velopment of a long basidium may be now summarised as follows. 

 The division of the fusion-nucleus into four nuclei takes from two 

 to three hours. The sterigmata begin to develop very shortly after 

 the last of the two nuclear divisions in the basidium-body has been 

 accomplished ; they complete their development in about two 

 and a half hours ; and, as soon as they have attained their full 

 length, they begin to develop spores at their free ends. The 

 growth of the spores from tiny rudiments to full size takes about 

 nine hours. The time required for the development of the spores 



1 Cf. vol. ii, 1922, pp. 8-9. 



