COPRINUS LAGOPUS ON BEET SEEDS 



75 



some of the material to Mr. Carleton Rea. Mr. Rea ^ regarded the 



fungus as Coprinus pilosus Beck, but sent some of the seeds to 



me with a request for my opinion. 



The Coprinus duly came up on 



some of the moistened seeds, and 



from its morphological characters 



I had no hesitation in concluding 



that it was identical with the form 



of C. lagopus which occurs very 



commonly on horse dung both in 



England and in Canada. A sketch 



of two rather small fruit-bodies 



which came up on the seeds is 



shown in Volume III, Fig. 141, D 



(p. 320).2 



In 1919, Pape 3 published a note 

 on the occurre^jce of a Coprinus on 

 germinating Mangel and Beet seeds. 

 His attention had been called to the 

 matter by Dr. Zade of Jena. Pape 

 observed that the fungus grew al- 

 most invariably on the seed-balls 

 (pericarps) themselves and he ob- 

 served nothing to suggest that the 

 fungus is a parasite. He says : 

 " The question of the significance of 

 the fungus in respect to the beet 

 seed upon which it grows must be 

 left open. A lowering of the germin- 

 ating power of the seed due to the 

 fungus or damage to the young 

 seedling from it has not been observed. The fact that the fungus 

 is most abundant upon seed which we found to have a low 



1 Carleton Rea, in litt. 



2 The occurrence of these fruit-bodies on seeds is referred to in the same volume 

 on p. 308. 



3 Pape, " Coprinus auf Riibensamen," Mitteilungen a. d. Biol. Reichsanst. f. 

 Land.- und Forstwirtschaft, Heft 17, 1919, pp. 13-16, with two illustrations. 



Fig. 47. — Coprinus niveus. A fruit- 

 body on horse dung in a dish 

 covered by a bell-jar. Spore- 

 discharge in progress. The edge 

 of the pilaus is revolute and 

 rolled. Water drops have been 

 excreted at the edge of the 

 pileus from those parts of the 

 gills which have already shed 

 their spores. Such an ex- 

 cretion only occurs when the 

 air is saturated or almost 

 saturated with water vapour, 

 and the drops may be derived 

 from water liberated and 

 sucked between the trama of 

 the gills during autodigestion. 

 Photographed in the laboratory 

 at Winnipeg. Natural size. 



