OCCURRENCE OF u FAIRY-RINGS." 2L 



1863, but since unmanured), on plot 3 (unmanured for more 

 than twenty years), and on plot 7 (with superphosphate of lime 

 and sulphates of potass, soda, and magnesia for twenty years). 

 On plots 4 . 1 and 8, on the other hand, they could be counted by 

 hundreds ; and on these two plots only were they found in " fairy- 

 rings." 



- On plot 4 . 1 (with superphosphate of lime alone) there were six 

 more or less complete "fairy-rings," on some of which hundreds 

 of the fungi were growing in thick patches, generally surrounded 

 hy the very luxuriant grass of the ring. 



On plot 8 (with superphosphate of lime and sulphates of soda 

 and magnesia but no potass for fourteen years) there were three 

 large " fairy-rings " with the fungi growing very thickly on them, 

 the grass of the rings being also very luxuriant. There were, 

 besides these rings, a number of patches down one side of the 

 plot showing many of the fungi and very luxuriant grass ; and 

 there was one large patch of very luxuriant grass showing no 

 fungi now, nor was mycelium found in the soil ; but in the autumn 

 this patch gave a crop of Agaricus nudus. On this plot especially 

 the increased growth of grass on the rings and patches where 

 fungi have occurred is so considerable that it must appreciably 

 affect the amount of produce on the plot ; and the grasses most 

 favoured seem to be JPoa trivialis and Holcus lanatus. 



- Thus, then, the highly nitrogenous fungi flourished strikingly, 

 and appeared in " fairy-rings," on two plots only, on neither of 

 which is either nitrogen or potass applied as manure — conditions 

 under which the development of the Graminaceae is extremely re- 

 stricted, and their limited growth is due to a deficient available 

 supply of nitrogen, or of potass, or of both, and where the com- 

 petition of the Leguminosse is also w r eak, in the absence of a more 

 liberal supply of potass. 



The questions obviously arise whether the greater prevalence 

 of fungi under such conditions be due to the manurial conditions 

 themselves being directly favourable for their growth, or whether 

 other plants, and especially the grasses, growing so sluggishly 

 under such conditions, the plants of the lower orders are the better 

 able to overcome the competition and to assert themselves. On 

 this point the further questions arise whether the fungi prevail 

 simply in virtue of the absence of adverse and vigorous competi- 

 tion, or whether to a greater or less extent as parasites, and so at 

 the expense of the sluggish underground growth of the plants in 



