Field Note. 301 



members repaired to the laboratory and grounds of the British 

 Botanical Association and Messrs. Backhouse's nurseries. 

 Afternoon tea was served, the members were photographed, 

 and much interest was shown in the valuable collection of 

 plants. On August 7th an excursion was made to Skipwith 

 Common. Here a hepatic new to Yorkshire was discovered 

 by a lady member. This proved to be Riccia crystallina, and 

 associated with it was Bot)ydiinn gramilatuin. The botanical 

 dinner at Davy Hall was largely attended, and the interest 

 enhanced by the presence of several foreign guests. They 

 made excellent speeches, which furnished another proof, if one 

 were needed, of the freemasonry of science. The meetings 

 were also taken advantage of by the Central Committee for 

 the survey and study of British vegetation, which met and 

 discussed various questions relating to survey work ; and on 

 Wednesday, under the leadership of Mr. C. E. Moss, the 

 members spent four days in studying the vegetation of the 

 North Derbyshire Moors. 



.\\OSSES. 

 Schistostega osmundacea Mohr. in Derbyshire. — I re- 

 cently found a fine growth of this beautiful moss in a small 

 heading- made in a gritstone quarry, situated about 850 feet 

 above sea-level and about one mile west of Wirksworth. Last 

 Sunday evening (July 2gth) I happened to visit the place about 

 an hour before sunset, and the time was ideal for showing off 

 the so-called luminous but really rather refractive properties 

 of the moss. The rays of the evening sun shone directly into 

 the heading, makings one side of it a sheet of pale metallic 

 green, one of my companions compared it to the peculiar 

 metallic green that we see on the breast of some Humming 

 Birds. This curious effect appears to reside not in the'fronds 

 of the moss but in the protonema, as looking closely into the 

 hole the dark fronds could be seen standing out against the 

 glittering green covering of the rock surface. When taken out 

 into full daylight the glittering appearance is quite lost and we 

 see only the moss fronds and a dull green alga-like growth 

 covering the sandstone. Sehistosfeg-a osmundacea grows in 

 several localities in Derbyshire, all of them upon the Millstone 

 grit, in crevices in the rock and often in rabbit burrows, but it has 

 not previously been recorded from the immediate neighbourhood 

 of Wirksworth. — T. Gibbs, Wirksworth, July 31st, 1906. 



1906 September i. 



