COPRINUS STERQUILINUS 



199 



left below to form a volva. However, this suggestion requires to 

 be put to the test of exact experiment. ^ 



The Structure and Development of the Hymenium. — The 

 structure of the hymenium of Coprinus sterquilinus is similar to 

 that of Coprinus comatus which was fully described in the last 

 Chapter. The elements of which the hymenium is composed are 

 basidia and paraphyses only, for cystidia are absent from the sides 

 of the gills. The basidia, as in most Coprini, are dimorphic : they 

 can be divided into two groups — long and short. As in Coprinus 



B 





'^^mm 







Fig. S4. — Coprinus sterquilinus. The hymenium seen in surface view. 

 A, plan of positions of the spores ; I, spores of long basidia ; s, spores 

 of short basidia. B, plan of positions of long basidia I, of short basidia 

 s, and of the paraphyses ]j. C, a combination of A and B showing the 

 hymenium with all its elements ; I, a long basidiimi ; s, a short 

 basidium ; p, paraphyses. The spores of the long basidia often stand 

 partly above the spores of the short basidia. Magnification, 293. 



comatus, the number of short basidia on a gill is approximately 

 equal to the number of long ones, but there is a slight preponder- 

 ance of the former. The long and the short basidia and the para- 

 physes are so arranged in relation to one another that the hymenium 

 as a whole can be considered as a living mosaic-work with a beautiful 

 pattern. 



In Fig. 84 is shown in face view a study of a piece of the 

 hymenium just before the beginning of spore-discharge. The 

 drawing A accurately represents the position of the spores of the 



^ The volva of Coprinus sterquilinus is not to be confused with the volva of 

 Amanita, for the former is only an adnate portion of the partial veil whereas the 

 latter is a remnant of the universal veil which at first enwrapped the whole fruit- 

 body. It is the annulus of Amanita which in reality corresponds with the so-called 

 volva of C. sterquilinus. 



