BOLBITIUS FLAVIDUS 75 



nicnt of the spores on several basidia was watched for some hours : 

 the spores were seen to begin their development as minute rudi- 

 ments on the ends of the sterigmata, grow to full size, remain 

 colourless for somewhat over an hour, and then become more and 

 more deeply coloured with a golden-yellow pigment ; but the 

 sterigmata ultimately collapsed and dragged the spores toward the 

 hymenium without discharging them. Complete normal develop- 

 ment and discharge, therefore, was not observed for any single 

 basidium. However, it is my opinion, based on these observations 

 and numerous observations of a more successful character with 

 other species, that several hours are required for a basidium of 

 Bolbitius flavidus to develop and ripen its spores up to the moment 

 of discharge. I am inclined to believe that these hours number 

 at least six and may be eight. If we assume that seven is the right 

 number, then we can calculate the length of the spore-discharge 

 period for those parts of the hymenium where four generations of 

 basidia can be made out definitely. After the first generation of 

 basidia has shed its spores, three other successive generations will 

 take about twenty-one hours to produce and shed their spores, i.e. 

 the spore-discharge period will be a little less than twenty-four 

 hours in length. 



Correlation of Facts. — Let us now attempt to correlate the 

 various facts connected with the organisation of the fruit-bodies. 

 The fruit-bodies of Bolbitius flavidus shed all their spores within 

 twenty-four hours and then immediately collapse ; and they 

 usually come up after rains when the air is moist and relatively 

 still. Since they have such an ephemeral existence under these 

 conditions, it is not necessary for them to be stoutly built like 

 Polypori, Boleti, Psalliota canipestris, Lepiota procera, etc., all of 

 which continue to shed spores for many days even during very dry 

 weather. Accordingly, we find that they are weak and watery : 

 for the maintenance of their rigidity they depend chiefly on the 

 turgor of their cells. The stipe is a hollow cylinder with a wide 

 cavity and relatively thin walls, and resembles the stipes of such 

 equally ephemeral fruit-bodies as Coprinus niveus and C. macro- 

 rhizus : the minimum amount of material is so disposed as to obtain 

 the maximum mechanical effect for resisting the strains to which 



