20 Dtt. J. H. GILBERT ON TIIE 



results of his observations on these points that I am enabled to 

 communicate. • 



Before stating under which of the conditions of manuring 

 14 fairy-rings " have most developed, it is of interest to observe 

 that, according to published analyses of various fungi, generally 

 from one fourth to one third of their dry substance consists of ni- 

 trogenous matters. The dry substance further generally contains 

 from 8 to 10 per cent, of mineral matter or ash, of which about 

 80 per cent, is phosphate of potassium. In fact, fungi would 

 appear to be among the most highly nitrogenous of plants, and 

 to be also very rich in potass. Yet the fungi have developed 

 in "fairy -rings" only on the plots poorest in nitrogen and 

 potass in such conditions as to be available to most other 

 plants. 



To go a little further into detail : — 



In November 1874 six species of fungi were observed on the 

 unmanured plot (3), where also they were more abundant than 

 on any other plot. They were named by the Eev. M. J. Berkeley 

 as follows — Boletus erythropus, Hygrophorus pratensis, H. coc- 

 cineus, H. virgineus, Agaricus geotrupus, A. czruginosus. 



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

 two species, namely Hygrophorus coccineus and Clavaria vermi- 

 cularis. 



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

 and magnesia, but without potass for fourteen years, two species, 

 Hygrophorus virgineus and Agaricus nudus. 



On plot 17, with nitrate of soda alone, small patches of Hygro- 

 pJiorus virgineus and of Agaricus furfuraceus were found. On 

 plot 16, with nitrate of soda and sulphates of potass, soda, and 

 magnesia, a few of Hygrophorus virgineus. And on one or two 

 other plots there were individual specimens of Agaricus arvensis 

 of very large size. 



"Fairy-rings" occurred almost exclusively on plot 4. 1 (with 

 superphosphate of lime alone), and on plot 8 (with superphosphate 

 of lime, and sulphates of soda and magnesia, but no potass). 



In May 1875 only one species, namely Marasmius oreadurn, was 

 observed. 



On the 19th there were comparatively few specimens to be 

 found. On the 31st they occurred in small numbers on plot 1 

 (with farm-yard manure and ammonia salts 1856-1863, but since 

 ammonia salts only), on plot 2 (with farm-yard manure alone 1856- 



