72 RESEARCHES ON FUNGI 



of this time to empty away most of the Hquid above the spores. 

 To make the ink suificiently adhesive, add some pieces of gum 

 arabic. To prevent the development of moulds and to improve the 

 odour, add some oil of cloves. Finally, shake up the whole and 

 store it in a stoppered bottle. The ink, before being used, should 

 be shaken, 



Boudier calls attention to the fact that Coprinus ink, although 

 easily washed away, is not readily altered by chemical reagents 

 such as oxalic acid, is only partially discoloured by chlorine and 

 hypochlorites, and owing to its microscopic characters (presence 

 of spores) is easily recognisable. He suggested that it should be 

 used for documents where forgeries might be attempted. 



Boudier further observed that the ink of Coprinus comatus 

 (Fig. 46 ; also Vol. Ill, Figs. 57 and 58, pp. 148 and 150) is not 

 nearly so good as the ink of C. atramentarius, but that it contains so 

 much natural mucilage that it is unnecessary to add any gum to it. 



The ink of Cojorinus atramentarius prepared with the addition 

 of an antiseptic has good keeping qualities. Some of this ink 

 prepared in my laboratory upwards of ten years ago appears to be 

 just as good as when first put into the bottle. Coprinus spores 

 do not readily undergo decomposition, and the way in which they 

 are destroyed under natural conditions still remains to be 

 investigated. 



Coprinus atramentarius ink is far better than C. sterquilinus ink. 

 The chief reason for this difference appears to be that in C. atra- 

 mentarius the spores are very small (10 x 5-5 [j.) and numerous, 

 whereas in C. sterquilinus they are very large (18 x 10-11 [i) and 

 relatively few. 



The Hyphal String in the Stipe of Coprinus comatus. — In a 

 stipe of Coprinus comatus or C. sterquilinus which is elongating 

 there is a soft loose hyphal string which extends through the centre 

 of the cavity from top to bottom. This hyphal string, as formed 

 in a fruit-body of C. comatus, is illustrated in the photograph repro- 

 duced in Fig. 46. The young stipe is made up of an outer firm 

 cylinder and of an inner softer core. The hyphae making up the 

 core are loosely netted. As the stipe, owing to the enlargement 

 of the firm cylinder, grows in length and diameter, it becomes 

 hollow, and the hyphae of the core become drawn more or less 



