146 Transactions British Mycological Society, 



breadths being 21-60 ju,x 10-16 /x respectively. They rarely pos- 

 sess more than two longitudinal divisions in any one transverse 

 stratum, and each cell contains one or two oil-drops embedded 

 in the pale green contents. The spore- walls both internally and 

 externally are free from corrugations and rugosities of any kind 

 and have rounded corners and are comparatively thick relatively 

 to the size of the spore. 



Young spores set free by crushing a fructification are generally 

 provided with a sporophore of about their own length, which 

 usually consists of two cells (Plate IV, fig. 5, a). When such 

 spores are put up in hanging drop cultures the sporophore 

 gradually undergoes mucilaginous degeneration and has entirely 

 disappeared before germination takes place (Plate IV, fig. 10, a) . 

 In fact the process which would normally take place within 

 the fructification is here continued after the liberation of the 

 immature spores. Stalked immature spores (Plate IV, fig. 5, a) 

 can be readily distinguished from germinating spores with a single 

 short germ-tube (Plate IV, fig. 9, a) by the fact that the latter 

 never possess a cross wall close to the spore whereas the former 

 always show the cross septum separating spore and sporophore. 



Simultaneously with the gradual progression downwards of 

 the spore-bearing layer, degeneration occurs in other parts of 

 the fructification. The mass of pale-coloured pseudoparenchyma 

 already referred to, which is found between the first formed 

 spores and the upper part of the wall, breaks down to a greater 

 or less degree, giving rise to a thin pale brown mucilage, which 

 ultimately escapes with the spores. The wall itself also becomes 

 mucilaginous; at a comparatively early stage, when only a 

 small number of spores have been produced it can be seen that 

 the apical portion has already become paler in colour (Plate III, 

 fig. i), this being the first indication of the process which will 

 ultimately result in the disappearance of the wall. Stages between 

 this and the complete mucilaginisation of this part of the wall 

 were not seen owing to the fact that at this period the latter 

 is so easily ruptured. There is no doubt however that the 

 process continues and the larger fructification seen in Plate III, 

 fig. 4 probably shows its completion. In this case a portion of the 

 upper part of the wall has completely disappeared, but few if 

 any of the spores have escaped. It is possible however that this 

 fructification has been ruptured in section cutting. 



The degeneration spreads to the lateral portions of the wall 

 and these are gradually disintegrated from above downwards. 

 As already described spore formation precedes mucilaginisation 

 of the wall and this initial advantage is retained throughout. 

 At any stage, therefore, the side walls project above the level 

 at which spore formation is taking place in the fructification. 



