GENERAL SUMMARY 297 



from below upwards ; but the gills are not destroyed by autodigestion 

 from below upwards. After spore-discharge is over, the gills are left 

 intact and are whitish owing to the black spores having disappeared 

 from the hymenium. 



The four spores of five individual basidia were shot away from their 

 sterigmata one after the other within fifteen seconds. 



The non-autodigestion of the gills in Co'prinus flicatilis is dis- 

 advantageous for the discharge of the spores only in a very limited 

 degree, as in this species the upper halves of the gills split down their 

 middle plane and the hymenium on the split halves looks more or less 

 downwards, so that the spores on these halves can be discharged into 

 the air without any mechanical hindrance. 



The species most nearly related to Coprinus pUcatilis appears to be 

 C. longipes which comes up on old horse dung in laboratory cultures at 

 Winnipeg. In C. longipes the gills undergo slight autodigestion at their 

 edges. 



Chapter III. — The relative efficiency of the Coprinus and Non- 

 Coprinus Types of fruit-body organisation has been discussed. The 

 Non-Coprinus Type, as represented by the Panaeolus Sub-type, produces 

 about three times as many spores per unit of area of the hymenium as 

 the Coprinus Type, but employs relatively much thicker gills on which 

 to develop the hymenium. The Coprinus Type, as represented by large 

 species such as Coprinus comatus and C. atramentarius, has much less 

 pileus-flesh than the Non-Coprinus Type, as represented by Psalliota 

 campestris. 



The nature of Coprinus ink is discussed and the way of making it. 

 The blackness of the ink is chiefly due to the presence of the spores, but 

 is in part due to the liquid portion of the ink, which is brown. The 

 brown colour of the spore-less juice is due to the action of oxidases. 



The hyphal string in the centre part of the hollow stipe of Coprinus 

 comatus has been illustrated. A record is made of the size of a giant 

 fruit-body of C. comatus found by Dr. C. W. Dodge in Costa Rica. 



An illustration is given of a pileus of Coprinus niveus which has 

 excreted drops of liquid. 



It has been shown that the Coprinus which grows on Beet and Mangel 

 seeds is Coprinus lagopus, and a photograph of the fungus growing on 

 Sugar-beet seeds is reproduced. 



Chapter IV.— In Coprinus sterquilinus , passage of the spores down 

 the alimentary canal of a horse is an essential feature in the life-history. 

 Only those spores which are embedded in horse-dung balls succeed in 

 producing mycelia which give rise to fruit-bodies. The results of 

 experiments appear to indicate that, under natural conditions, wind- 

 blown spores which settle on horse-dung after this has been deposited 

 have practically no chance of ever producing mycelia which are effective 

 in reproduction. 



