Pileate and Clavate Tribes of Hymenomycetous Fungi. 91 



600 diameters to trace the cellular texture of the substance in- 

 terposed between the two layers of the hymenium, though in an 

 extremely thin slice cut in the direction of the gill there was a 

 faint trace of lines running in the direction of the section. There 

 was scarcely any change so long as the margin of the pileus was 

 not detached from the stem ; but in an individual a little more 

 advanced some of the cells were found to have acquired a more 

 cylindrical form, having grown faster than the others, and in 

 consequence to project beyond them. The intermediate sub- 

 stance was now seen to consist of elongated, somewhat anasto- 

 mosing cells, coated on either side by a layer of shorter ones, 

 which are subglobose. The contents of the cells of the hyme- 

 nium are grumous. As the pileus expands, the tips of some 

 of the more elongated cells, or, if I may so call them, sporo- 

 phores, show four minute points disposed nearly in a square, 

 which rapidly increase in length till they are about half as 

 long as the portion of the sporophore which is emersed. In 

 this stage of growth they are slightly curved inwards. On 

 the tip of each of these a minute globule is soon developed, 

 which is at first perfectly pellucid. This rapidly increases, 

 acquiring an oval form, though more gibbous on the side 

 which is turned from the axis of the sporophore, so that the 

 position of the perfect spores upon the spicules is oblique. 

 The apex becomes minutely papillate, and at the base there is 

 a very short peduncle. The grumous contents of the spores, 

 which were at first almost colourless, acquire in the perfect 

 fruit a rich purple brown. The contents of the sporophores 

 as they increase become more distinctly granular, and are at- 

 tracted towards the apex as the spores are developed, which 

 appear to be nourished by them. When the spores are per- 

 fected the sporophores are nearly empty. 



It is to be observed that the sporophores in the mature 

 plant are not all of the same height. In looking down upon 

 a thin slice from the surface of the gill, the lowest, which are 

 frequently without spores, appear like circles ; others are ob- 

 served to be furnished with four spiculae ; and it is not uncom- 

 mon, when the gill has not acquired its deepest tint, to see 

 the spores themselves in various stages of development. The 



