PANAEOLUS CAMPANULATUS 285 



9 seconds old. 1 The basidia V, VI, VII . . . XII will all discharge 

 their spores in succession, V first and XII last. The basidia opposite 

 the Arabic numerals 1, 2, 3 . . . 11 have developed spores in the 

 area A and will develop spores in the remaining areas, in their 

 numerical order. It will be noticed that the basidia 1, 2, and 3 

 bear spores of progressively smaller size. Basidium 4 possesses 

 full-grown sterigmata but no spores. The sterigmata on basidia 

 4, 5, and 6 are progressively shorter. Basidium 7, although fully 

 protuberant, has not yet developed even the bases of its sterigmata, 

 and basidia 8, 9, 10, and 11 are in the same condition. They will 

 all develop their sterigmata in succession following their numerical 

 order. The series of basidia 1, 2, 3 ... 11 are developmentally 

 about eight hours behind the adjacent series of basidia I, II, 

 III . . . XII. Thus basidium 1 is about eight hours behind 

 basidium I, basidium 5 about eight hours behind basidium V, 

 basidium 10 about eight hours behind basidium XII, and so forth. 



Another wave of development in the hymenium is shown on 

 the right-hand side of Fig. 96 as passing from below upwards. 

 There is a series of basidia indicated by the Roman numerals 

 I, II, III . . . XI, where I is the oldest, II slightly younger, 

 III still younger, and so on up to XI. Similarly, in the series of 

 basidia indicated by the Arabic numerals 1, 2, 3 . . . 12, basidium 

 1 is the oldest, basidium 2 slightly younger, basidium 3 still younger, 

 and so on up to basidium 12. Here again, the series 1, 2, 3 . . . 

 12 is developmentally about eight hours behind the series I, II, 

 III ... XI. 



The developmental waves shown in the hymenium on both 

 sides of Fig. 96 correspond in their nature to the wave ac to 6 shown 

 in the surface view represented in Fig. 90 (p. 258), for they are 

 continuous in one direction. In the surface view represented in 

 Fig. 89 (p. 257), a wave is shown which has originated at the 

 periphery of the area and is spreading centripetally, i.e. toward 

 the centre of the central black area. If one wanted to represent 

 a cross-section through a wave area of this type, one could 



1 The spores, normally, are shot away about 10 seconds after the water-drop 

 begins to be excreted and immediately after it has attained full normal size. Vide 

 Chap. I. 



