PANAEOLUS CAMPANULATUS 305 



inefficient mode of spore-discharge. We shall now study the wasted 

 spores a little more closely. We shall first estimate their number, 

 and then pass on to discuss a curious accident which may befall 

 them at the moment when they should be liberated. 



In order to find out the number of wasted spores which may 

 be present on a fruit-body of Panaeolus campanulatus, a culture 

 of this species was made on horse dung in the laboratory under 

 a large bell-jar. The first large fruit-body which came up was 

 chosen for observation. During its spore-discharge period, which 

 lasted about ten days, care was taken not to disturb it in any 

 way. As soon as the spores had ceased to be liberated, the ex- 

 hausted gills were examined under the microscope. A camera-lucida 

 sketch of all the collapsed basidia and of all the wasted spores 

 was made for an area of the hymenium which just filled the field 

 of view (Fig. 103). The number of wasted spores was easily 

 counted. The total number of spores which the whole area had 

 produced was evidently equal to the number of sterigmatic stumps, 

 and it. was obtained by counting the exhausted basidia and 

 multiplying the number found by 4. The total number of 

 spores produced on the area was 1,832, of which 70 had been 

 wasted. The wasted spores, therefore, formed only 3-8 per cent. 

 of the whole number produced. In respect to the number of 

 wasted spores, the area chosen for investigation was, so far as 

 I could judge from inspection, of average character. Some areas, 

 however, were richer in wasted spores and some poorer. In one 

 of the poorer fields, which was equal in extent to the one already 

 illustrated, only a single wasted spore could be observed, and in 

 another only 15. From the results of these observations I think 

 it would be safe to say that, for the fruit-body investigated, the 

 wasted spores were approximately from 3 to 4 per cent, of the 

 whole number produced. 



By tracing the outlines of the gills removed from one quarter of 

 the pileus and measuring their superficial areas, both sides of each gill 

 being taken into account, it was calculated that for the whole pileus : 



the 60 long gills had a superficial area of about 60 square cm., 

 the 60 intermediate gills had an area of about 24 square cm., 

 the 120 short gills had an area of about 4 square cm., 



VOL. II. X 



