GERMINATION AT A LOW TEMPERATURE 89 



sizes, selected from fifty different fruit-bodies, singly in sterile 

 hanging drops of nutrient gelatine (containing dextrose, peptone, 

 beef -extract, and sodium chloride), with the result that 101, or 

 23-3 per cent., germinated. 



High Temperature Not Required for Germination. — In another 

 series of experiments, made to test Miss Baden's assertion that the 

 spores of Coprinus sterquilinus will not germinate at all below a 

 temperature of 20° C, hanging drops, similar to those already 

 described, were made for all the five kinds of media ; and then the 

 culture apparatus was set in a refrigerator in which the temperature 

 varied from 5° to 10° C. Under these conditions, the first signs of 

 germination usually appeared about 36 hours after the spores had 

 been sown ; but, in the end, from 80 to 90 per cent, of the total 

 number of spores germinated, just as in the experiments made at 

 30° C. This successful series of experiments, carried out at tem- 

 peratures far below 20° C, seems to prove conclusively that Miss 

 Baden's assertion was based on an insufficient number of experi- 

 ments. In such a matter as the one under discussion, a series of 

 positive results by far out- weighs in importance a large number of 

 negative ones. 



Germination of Spores immediately after their Discharge. — 

 According to Miss Baden,i the spores of Coprinus sterquilinus do 

 not mature until about three weeks after they have been shed but, 

 if dried for two days at 40° C, they germinate at once. She there- 

 fore supposed that, under natural conditions, the germination of 

 the spores in horse dung is retarded until the substratum has become 

 fairly dry and such fungi as Mucor have disappeared. In the 

 course of many years I have made numerous pure cultures of C 

 sterquilinus by inoculating sterilised horse dung with spores which 

 fell on to the medium directly from the gills ; and Hanna,^ in the 

 course of his work, could observe no difference between the germina- 

 tion of spores which had just been shed and of spores which had 

 been kept for several weeks. In one of Hanna's experiments ten 

 spores which had just been shed were placed in as many hanging- 

 drops of sterile nutrient gelatine, with the result that, within 

 24 hours, all of them germinated. There can be no doubt, 



1 M. L. Baden, loc. cit., pp. 135-142. 2 vv. F. Hanna, loc. cit., p. 225. 



